Six Day ago kontact crashes after reading mails. Changing to a trash folder on imap. Deleting one message there with the clean all trash function from file menu. Changing to an other imap folder in the same account. Then crash.

---------
BACKTRACE

Anwendung: Kontact (kontact), Signal SIGABRT
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread 0xb4db3720 (LWP 6557)]
[KCrash handler]
#6  0xb7f1b410 in __kernel_vsyscall ()
#7  0xb6b40085 in raise () from /lib/tls/i686/cmov/libc.so.6
#8  0xb6b41a01 in abort () from /lib/tls/i686/cmov/libc.so.6
#9  0xb6b3910e in __assert_fail () from /lib/tls/i686/cmov/libc.so.6
#10 0xb198fd54 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#11 0xb199fbe2 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#12 0xb18eaad6 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#13 0xb1a7254c in KMMainWidget::closeFolder ()
   from /usr/lib/kde4/lib/libkmailprivate.so.4
#14 0xb1a83c7d in KMMainWidget::folderSelected ()
   from /usr/lib/kde4/lib/libkmailprivate.so.4
#15 0xb1a8e424 in KMMainWidget::qt_metacall ()
   from /usr/lib/kde4/lib/libkmailprivate.so.4
#16 0xb77dff79 in QMetaObject::activate (sender=0x8753048, 
    from_signal_index=133, to_signal_index=133, argv=0xbfb674ac)
    at kernel/qobject.cpp:3016
#17 0xb77e0642 in QMetaObject::activate (sender=0x8753048, m=0xb1d0a028, 
    local_signal_index=0, argv=0xbfb674ac) at kernel/qobject.cpp:3086
#18 0xb18817f3 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#19 0xb188751f in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#20 0xb1888c09 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#21 0xb6150821 in Q3ScrollView::viewportMouseReleaseEvent (this=0x8753048, 
    e=0xbfb67b0c) at widgets/q3scrollview.cpp:1761
#22 0xb6152228 in Q3ScrollView::eventFilter (this=0x8753048, obj=0x87537f0, 
    e=0xbfb67b0c) at widgets/q3scrollview.cpp:1479
#23 0xb60f5896 in Q3ListView::eventFilter (this=0x8753048, o=0x87537f0, 
    e=0xbfb67b0c) at itemviews/q3listview.cpp:3777
#24 0xb1883030 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#25 0xb77cb431 in QCoreApplicationPrivate::sendThroughObjectEventFilters (
    this=0x8064600, receiver=0x87537f0, event=0xbfb67b0c)
    at kernel/qcoreapplication.cpp:698
#26 0xb6e91f73 in QApplicationPrivate::notify_helper (this=0x8064600, 
    receiver=0x87537f0, e=0xbfb67b0c) at kernel/qapplication.cpp:3796
#27 0xb6e97125 in QApplication::notify (this=0xbfb682d8, receiver=0x87537f0, 
    e=0xbfb67b0c) at kernel/qapplication.cpp:3527
#28 0xb7c65483 in KApplication::notify (this=0xbfb682d8, receiver=0x87537f0, 
    event=0xbfb67b0c)
    at /build/buildd/kde4libs-4.1.2/kdeui/kernel/kapplication.cpp:311
#29 0xb77cb0b9 in QCoreApplication::notifyInternal (this=0xbfb682d8, 
    receiver=0x87537f0, event=0xbfb67b0c) at kernel/qcoreapplication.cpp:591
#30 0xb6e94661 in QApplicationPrivate::sendMouseEvent (receiver=0x87537f0, 
    event=0xbfb67b0c, alienWidget=0x87537f0, nativeWidget=0x818bb48, 
    buttonDown=0xb7687a10, lastMouseReceiver=@0xb7687a14)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#31 0xb6efe52d in QETWidget::translateMouseEvent (this=0x818bb48, 
    event=0xbfb68028) at kernel/qapplication_x11.cpp:4048
#32 0xb6efcee1 in QApplication::x11ProcessEvent (this=0xbfb682d8, 
    event=0xbfb68028) at kernel/qapplication_x11.cpp:3166
#33 0xb6f25c2a in x11EventSourceDispatch (s=0x8067498, callback=0, 
    user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:148
#34 0xb5669dd6 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#35 0xb566d193 in ?? () from /usr/lib/libglib-2.0.so.0
#36 0xb566d74e in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#37 0xb77f69f8 in QEventDispatcherGlib::processEvents (this=0x8063c20, 
    flags=@0xbfb681c8) at kernel/qeventdispatcher_glib.cpp:325
#38 0xb6f25a25 in QGuiEventDispatcherGlib::processEvents (this=0x8063c20, 
    flags=@0xbfb681f8) at kernel/qguieventdispatcher_glib.cpp:204
#39 0xb77ca33d in QEventLoop::processEvents (this=0xbfb68270, 
    flags=@0xbfb68234) at kernel/qeventloop.cpp:149
#40 0xb77ca4cd in QEventLoop::exec (this=0xbfb68270, flags=@0xbfb68278)
    at kernel/qeventloop.cpp:200
#41 0xb77cc74d in QCoreApplication::exec () at kernel/qcoreapplication.cpp:849
#42 0xb6e91897 in QApplication::exec () at kernel/qapplication.cpp:3330
#43 0x0804b326 in _start ()
#0  0xb7f1b410 in __kernel_vsyscall ()

Three weeks ago (So this was kde 4.1.1!) it goes like:

Using "File -> Empty All Trash Folders". Going to an other imap folder. Delete one message. Go to another imap folder. Then the crash happened.

--------------
BACKTRACE

Anwendung: Kontact (kontact), Signal SIGABRT
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread 0xb4e33940 (LWP 20796)]
[KCrash handler]
#6  0xb7f93410 in __kernel_vsyscall ()
#7  0xb6bb8085 in raise () from /lib/tls/i686/cmov/libc.so.6
#8  0xb6bb9a01 in abort () from /lib/tls/i686/cmov/libc.so.6
#9  0xb6bb110e in __assert_fail () from /lib/tls/i686/cmov/libc.so.6
#10 0xb19f0a37 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#11 0xb19fe1b4 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#12 0xb1a03b62 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#13 0xb7857f79 in QMetaObject::activate (sender=0x87fb5e0, 
    from_signal_index=40, to_signal_index=40, argv=0xbfdbac08)
    at kernel/qobject.cpp:3016
#14 0xb7858642 in QMetaObject::activate (sender=0x87fb5e0, m=0xb6b489b0, 
    local_signal_index=0, argv=0xbfdbac08) at kernel/qobject.cpp:3086
#15 0xb69df6d9 in KIO::TransferJob::data (this=0x87fb5e0, _t1=0x87fb5e0, 
    _t2=@0xbfdbae84)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/obj-i486-linux-gnu/kio/jobclasses.moc:356
#16 0xb69e00f5 in KIO::TransferJob::slotData (this=0x87fb5e0, 
    _data=@0xbfdbae84)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kio/kio/job.cpp:927
#17 0xb69ea2a2 in KIO::TransferJob::qt_metacall (this=0x87fb5e0, 
    _c=QMetaObject::InvokeMetaMethod, _id=8, _a=0xbfdbad2c)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/obj-i486-linux-gnu/kio/jobclasses.moc:337
#18 0xb7857f79 in QMetaObject::activate (sender=0x8808ea8, 
    from_signal_index=4, to_signal_index=4, argv=0xbfdbad2c)
    at kernel/qobject.cpp:3016
#19 0xb7858642 in QMetaObject::activate (sender=0x8808ea8, m=0xb6b4b3e4, 
    local_signal_index=0, argv=0xbfdbad2c) at kernel/qobject.cpp:3086
#20 0xb6a84f13 in KIO::SlaveInterface::data (this=0x8808ea8, _t1=@0xbfdbae84)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/obj-i486-linux-gnu/kio/slaveinterface.moc:136
#21 0xb6a87133 in KIO::SlaveInterface::dispatch (this=0x8808ea8, _cmd=100, 
    rawdata=@0xbfdbae84)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kio/kio/slaveinterface.cpp:162
#22 0xb6a8741d in KIO::SlaveInterface::dispatch (this=0x8808ea8)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kio/kio/slaveinterface.cpp:90
#23 0xb6a79fd7 in KIO::Slave::gotInput (this=0x8808ea8)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kio/kio/slave.cpp:319
#24 0xb6a7b3ad in KIO::Slave::qt_metacall (this=0x8808ea8, 
    _c=QMetaObject::InvokeMetaMethod, _id=2, _a=0xbfdbaf98)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/obj-i486-linux-gnu/kio/slave.moc:75
#25 0xb7857f79 in QMetaObject::activate (sender=0x8809830, 
    from_signal_index=4, to_signal_index=4, argv=0x0)
    at kernel/qobject.cpp:3016
#26 0xb7858642 in QMetaObject::activate (sender=0x8809830, m=0xb6b48040, 
    local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3086
#27 0xb69b67c7 in KIO::Connection::readyRead (this=0x8809830)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/obj-i486-linux-gnu/kio/connection.moc:84
#28 0xb69b7638 in KIO::ConnectionPrivate::dequeue (this=0x8809850)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kio/kio/connection.cpp:82
#29 0xb69b847e in KIO::Connection::qt_metacall (this=0x8809830, 
    _c=QMetaObject::InvokeMetaMethod, _id=1, _a=0x85d5348)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/obj-i486-linux-gnu/kio/connection.moc:72
#30 0xb78518ab in QMetaCallEvent::placeMetaCall (this=0x8604b00, 
    object=0x8809830) at kernel/qobject.cpp:535
#31 0xb7852c31 in QObject::event (this=0x8809830, e=0x8604b00)
    at kernel/qobject.cpp:1140
#32 0xb6f09f9c in QApplicationPrivate::notify_helper (this=0x8064608, 
    receiver=0x8809830, e=0x8604b00) at kernel/qapplication.cpp:3800
#33 0xb6f0ebf9 in QApplication::notify (this=0xbfdbb7a8, receiver=0x8809830, 
    e=0x8604b00) at kernel/qapplication.cpp:3392
#34 0xb7cdc1c3 in KApplication::notify (this=0xbfdbb7a8, receiver=0x8809830, 
    event=0x8604b00)
    at /build/buildd/kde4libs-4.1.1+really4.1.1/kdeui/kernel/kapplication.cpp:311
#35 0xb78430b9 in QCoreApplication::notifyInternal (this=0xbfdbb7a8, 
    receiver=0x8809830, event=0x8604b00) at kernel/qcoreapplication.cpp:591
#36 0xb7844469 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, 
    event_type=0, data=0x804f840)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#37 0xb784468d in QCoreApplication::sendPostedEvents (receiver=0x0, 
    event_type=0) at kernel/qcoreapplication.cpp:1095
#38 0xb786e62f in postEventSourceDispatch (s=0x8066750)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#39 0xb56eadd6 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#40 0xb56ee193 in ?? () from /usr/lib/libglib-2.0.so.0
#41 0xb56ee74e in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#42 0xb786e9f8 in QEventDispatcherGlib::processEvents (this=0x80636b0, 
    flags=@0xbfdbb698) at kernel/qeventdispatcher_glib.cpp:325
#43 0xb6f9da25 in QGuiEventDispatcherGlib::processEvents (this=0x80636b0, 
    flags=@0xbfdbb6c8) at kernel/qguieventdispatcher_glib.cpp:204
#44 0xb784233d in QEventLoop::processEvents (this=0xbfdbb740, 
    flags=@0xbfdbb704) at kernel/qeventloop.cpp:149
#45 0xb78424cd in QEventLoop::exec (this=0xbfdbb740, flags=@0xbfdbb748)
    at kernel/qeventloop.cpp:200
#46 0xb784474d in QCoreApplication::exec () at kernel/qcoreapplication.cpp:849
#47 0xb6f09897 in QApplication::exec () at kernel/qapplication.cpp:3330
#48 0x0804b326 in _start ()
#0  0xb7f93410 in __kernel_vsyscall ()

On 08/24/2008 this one happened (other Computer, fresh Kubuntu 8.04 with kde4-backports):

Moved some mails between IMAP accounts and deleted a few. After that I cleared all Trashes with "Empty All Trash Folders" from "File" menu. At last I select an other directory in another IMAP account. After this Kontact crashed with SIGABRT.

------------
BACKTRACE

Anwendung: Kontact (kontact), Signal SIGABRT
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread 0xb4dd5940 (LWP 11787)]
[New Thread 0xab0cdb90 (LWP 11893)]
[New Thread 0xb0fedb90 (LWP 11839)]
[KCrash handler]
#6  0xb7f0f410 in __kernel_vsyscall ()
#7  0xb6b4c085 in raise () from /lib/tls/i686/cmov/libc.so.6
#8  0xb6b4da01 in abort () from /lib/tls/i686/cmov/libc.so.6
#9  0xb6b4510e in __assert_fail () from /lib/tls/i686/cmov/libc.so.6
#10 0xb1a2d484 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#11 0xb1a3d3d2 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#12 0xb19883d6 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#13 0xb1b0f59c in KMMainWidget::closeFolder ()
   from /usr/lib/kde4/lib/libkmailprivate.so.4
#14 0xb1b2117d in KMMainWidget::folderSelected ()
   from /usr/lib/kde4/lib/libkmailprivate.so.4
#15 0xb1b2b9e4 in KMMainWidget::qt_metacall ()
   from /usr/lib/kde4/lib/libkmailprivate.so.4
#16 0xb77e24f9 in QMetaObject::activate (sender=0x8850ce8, 
    from_signal_index=133, to_signal_index=133, argv=0xbf99eaec)
    at kernel/qobject.cpp:3010
#17 0xb77e2bc2 in QMetaObject::activate (sender=0x8850ce8, m=0xb1da67c8, 
    local_signal_index=0, argv=0xbf99eaec) at kernel/qobject.cpp:3080
#18 0xb191f263 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#19 0xb1924f4f in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#20 0xb1926639 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#21 0xb616a8c1 in Q3ScrollView::viewportMouseReleaseEvent (this=0x8850ce8, 
    e=0xbf99f13c) at widgets/q3scrollview.cpp:1761
#22 0xb616c2c8 in Q3ScrollView::eventFilter (this=0x8850ce8, obj=0x88514a8, 
    e=0xbf99f13c) at widgets/q3scrollview.cpp:1479
#23 0xb610f936 in Q3ListView::eventFilter (this=0x8850ce8, o=0x88514a8, 
    e=0xbf99f13c) at itemviews/q3listview.cpp:3777
#24 0xb1920a60 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#25 0xb77cda21 in QCoreApplicationPrivate::sendThroughObjectEventFilters (
    this=0x8064608, receiver=0x88514a8, event=0xbf99f13c)
    at kernel/qcoreapplication.cpp:694
#26 0xb6e9dbe3 in QApplicationPrivate::notify_helper (this=0x8064608, 
    receiver=0x88514a8, e=0xbf99f13c) at kernel/qapplication.cpp:3768
#27 0xb6ea2cc5 in QApplication::notify (this=0xbf99f908, receiver=0x88514a8, 
    e=0xbf99f13c) at kernel/qapplication.cpp:3501
#28 0xb7c5af53 in KApplication::notify (this=0xbf99f908, receiver=0x88514a8, 
    event=0xbf99f13c)
    at /build/buildd/kde4libs-4.1.0/kdeui/kernel/kapplication.cpp:311
#29 0xb77cd6a9 in QCoreApplication::notifyInternal (this=0xbf99f908, 
    receiver=0x88514a8, event=0xbf99f13c) at kernel/qcoreapplication.cpp:587
#30 0xb6e9fe11 in QApplicationPrivate::sendMouseEvent (receiver=0x88514a8, 
    event=0xbf99f13c, alienWidget=0x88514a8, nativeWidget=0x8188b48, 
    buttonDown=0xb768a850, lastMouseReceiver=@0xb768a854)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#31 0xb6f09cbd in QETWidget::translateMouseEvent (this=0x8188b48, 
    event=0xbf99f658) at kernel/qapplication_x11.cpp:4133
#32 0xb6f086a1 in QApplication::x11ProcessEvent (this=0xbf99f908, 
    event=0xbf99f658) at kernel/qapplication_x11.cpp:3255
#33 0xb6f3139a in x11EventSourceDispatch (s=0x8067390, callback=0, 
    user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:148
#34 0xb5686dd6 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#35 0xb568a193 in ?? () from /usr/lib/libglib-2.0.so.0
#36 0xb568a74e in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#37 0xb77f8f98 in QEventDispatcherGlib::processEvents (this=0x805c908, 
    flags=@0xbf99f7f8) at kernel/qeventdispatcher_glib.cpp:325
#38 0xb6f31195 in QGuiEventDispatcherGlib::processEvents (this=0x805c908, 
    flags=@0xbf99f828) at kernel/qguieventdispatcher_glib.cpp:204
#39 0xb77cc92d in QEventLoop::processEvents (this=0xbf99f8a0, 
    flags=@0xbf99f864) at kernel/qeventloop.cpp:149
#40 0xb77ccabd in QEventLoop::exec (this=0xbf99f8a0, flags=@0xbf99f8a8)
    at kernel/qeventloop.cpp:200
#41 0xb77ced3d in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845
#42 0xb6e9d567 in QApplication::exec () at kernel/qapplication.cpp:3304
#43 0x0804b326 in _start ()
#0  0xb7f0f410 in __kernel_vsyscall ()

And here's the last one for this session:

On 08/24/2008 another one happened (in the same session like the last post): 

"Empty all Trash Folders",
Switch to an subfolder on an other imap account,
reading and deleting mails there.
-> Crash

-----------
BACKTRACE

Anwendung: Kontact (kontact), Signal SIGABRT
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread 0xb4e17940 (LWP 6501)]
[KCrash handler]
#6  0xb7f54410 in __kernel_vsyscall ()
#7  0xb6b8e085 in raise () from /lib/tls/i686/cmov/libc.so.6
#8  0xb6b8fa01 in abort () from /lib/tls/i686/cmov/libc.so.6
#9  0xb6b8710e in __assert_fail () from /lib/tls/i686/cmov/libc.so.6
#10 0xb1a6c2a7 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#11 0xb1a79a24 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#12 0xb1a7f3d2 in ?? () from /usr/lib/kde4/lib/libkmailprivate.so.4
#13 0xb78244f9 in QMetaObject::activate (sender=0x9028c70, 
    from_signal_index=40, to_signal_index=40, argv=0xbfbca7a8)
    at kernel/qobject.cpp:3010
#14 0xb7824bc2 in QMetaObject::activate (sender=0x9028c70, m=0xb6b1e3b0, 
    local_signal_index=0, argv=0xbfbca7a8) at kernel/qobject.cpp:3080
#15 0xb69b53d9 in KIO::TransferJob::data (this=0x9028c70, _t1=0x9028c70, 
    _t2=@0xbfbcaa24)
    at /build/buildd/kde4libs-4.1.0/obj-i486-linux-gnu/kio/jobclasses.moc:356
#16 0xb69b5df5 in KIO::TransferJob::slotData (this=0x9028c70, 
    _data=@0xbfbcaa24) at /build/buildd/kde4libs-4.1.0/kio/kio/job.cpp:927
#17 0xb69bffa2 in KIO::TransferJob::qt_metacall (this=0x9028c70, 
    _c=QMetaObject::InvokeMetaMethod, _id=8, _a=0xbfbca8cc)
    at /build/buildd/kde4libs-4.1.0/obj-i486-linux-gnu/kio/jobclasses.moc:337
#18 0xb78244f9 in QMetaObject::activate (sender=0x8754298, 
    from_signal_index=4, to_signal_index=4, argv=0xbfbca8cc)
    at kernel/qobject.cpp:3010
#19 0xb7824bc2 in QMetaObject::activate (sender=0x8754298, m=0xb6b20de4, 
    local_signal_index=0, argv=0xbfbca8cc) at kernel/qobject.cpp:3080
#20 0xb6a5ad03 in KIO::SlaveInterface::data (this=0x8754298, _t1=@0xbfbcaa24)
    at /build/buildd/kde4libs-4.1.0/obj-i486-linux-gnu/kio/slaveinterface.moc:136
#21 0xb6a5cf23 in KIO::SlaveInterface::dispatch (this=0x8754298, _cmd=100, 
    rawdata=@0xbfbcaa24)
    at /build/buildd/kde4libs-4.1.0/kio/kio/slaveinterface.cpp:162
#22 0xb6a5d20d in KIO::SlaveInterface::dispatch (this=0x8754298)
    at /build/buildd/kde4libs-4.1.0/kio/kio/slaveinterface.cpp:90
#23 0xb6a4fdc7 in KIO::Slave::gotInput (this=0x8754298)
    at /build/buildd/kde4libs-4.1.0/kio/kio/slave.cpp:319
#24 0xb6a5119d in KIO::Slave::qt_metacall (this=0x8754298, 
    _c=QMetaObject::InvokeMetaMethod, _id=2, _a=0xbfbcab38)
    at /build/buildd/kde4libs-4.1.0/obj-i486-linux-gnu/kio/slave.moc:75
#25 0xb78244f9 in QMetaObject::activate (sender=0x88e1da8, 
    from_signal_index=4, to_signal_index=4, argv=0x0)
    at kernel/qobject.cpp:3010
#26 0xb7824bc2 in QMetaObject::activate (sender=0x88e1da8, m=0xb6b1da40, 
    local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3080
#27 0xb698c6b7 in KIO::Connection::readyRead (this=0x88e1da8)
    at /build/buildd/kde4libs-4.1.0/obj-i486-linux-gnu/kio/connection.moc:84
#28 0xb698d528 in KIO::ConnectionPrivate::dequeue (this=0x8754698)
    at /build/buildd/kde4libs-4.1.0/kio/kio/connection.cpp:82
#29 0xb698e36e in KIO::Connection::qt_metacall (this=0x88e1da8, 
    _c=QMetaObject::InvokeMetaMethod, _id=1, _a=0x91328b8)
    at /build/buildd/kde4libs-4.1.0/obj-i486-linux-gnu/kio/connection.moc:72
#30 0xb781de8b in QMetaCallEvent::placeMetaCall (this=0x8c4a4b0, 
    object=0x88e1da8) at kernel/qobject.cpp:535
#31 0xb781fed1 in QObject::event (this=0x88e1da8, e=0x8c4a4b0)
    at kernel/qobject.cpp:1140
#32 0xb6edfc0c in QApplicationPrivate::notify_helper (this=0x8064608, 
    receiver=0x88e1da8, e=0x8c4a4b0) at kernel/qapplication.cpp:3772
#33 0xb6ee4799 in QApplication::notify (this=0xbfbcb338, receiver=0x88e1da8, 
    e=0x8c4a4b0) at kernel/qapplication.cpp:3366
#34 0xb7c9ff53 in KApplication::notify (this=0xbfbcb338, receiver=0x88e1da8, 
    event=0x8c4a4b0)
    at /build/buildd/kde4libs-4.1.0/kdeui/kernel/kapplication.cpp:311
#35 0xb780f6a9 in QCoreApplication::notifyInternal (this=0xbfbcb338, 
    receiver=0x88e1da8, event=0x8c4a4b0) at kernel/qcoreapplication.cpp:587
#36 0xb7810a59 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, 
    event_type=0, data=0x804f840)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#37 0xb7810c7d in QCoreApplication::sendPostedEvents (receiver=0x0, 
    event_type=0) at kernel/qcoreapplication.cpp:1091
#38 0xb783abcf in postEventSourceDispatch (s=0x8066750)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#39 0xb56c8dd6 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#40 0xb56cc193 in ?? () from /usr/lib/libglib-2.0.so.0
#41 0xb56cc74e in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#42 0xb783af98 in QEventDispatcherGlib::processEvents (this=0x805c908, 
    flags=@0xbfbcb228) at kernel/qeventdispatcher_glib.cpp:325
#43 0xb6f73195 in QGuiEventDispatcherGlib::processEvents (this=0x805c908, 
    flags=@0xbfbcb258) at kernel/qguieventdispatcher_glib.cpp:204
#44 0xb780e92d in QEventLoop::processEvents (this=0xbfbcb2d0, 
    flags=@0xbfbcb294) at kernel/qeventloop.cpp:149
#45 0xb780eabd in QEventLoop::exec (this=0xbfbcb2d0, flags=@0xbfbcb2d8)
    at kernel/qeventloop.cpp:200
#46 0xb7810d3d in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845
#47 0xb6edf567 in QApplication::exec () at kernel/qapplication.cpp:3304
#48 0x0804b326 in _start ()
#0  0xb7f54410 in __kernel_vsyscall ()

@Christian: this report is a mess :P.
A tip: before adding new crash information / backtrace to a report, look if they are really the same backtrace or situation. If the new one is different you need to file a new different bug report, since it is a different issue.

When using different reports for different bugs it's easier for developers and bugtracker maintainers to look at them. Later, we can decide if they are related / the same issue, in order to merge them. But we can't split them if they are already like this report.

We will do something like this:

Backtraces from comment 0 , comment 2 and comment 4 are some issue.
Backtraces from comment 1 and comment 3 seem to be a different issue.

Can you file a new bug report for the crashes in comment 1 and comment 3 ? so this report will be based on the information of comment 0 (the original report), comment 2 and comment 4.

Anyway.. you need to install debug symbols packages in order to get more information of the crash.

If you can reproduce the crash at will in a recent KDE (4.1.4 / 4.2beta2 / 4.2rc1 / 4.2svn / 4.3svn) , may you read http://techbase.kde.org/Development/Tutorials/Debugging/How_to_create_useful_crash_reports and post a complete backtrace? 

Thanks a lot :)