Application that crashed: kmail
Version of the application: 1.12.1
KDE Version: 4.3.1 (KDE 4.3.1)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-999-generic i686
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
After running kmail for a while (and after downloading aprox. 15000 messages via pop3) I wanted to empty the trash folder...

 -- Backtrace:
Application: KMail (kmail), signal: Segmentation fault
[KCrash Handler]
#6  KIO::Slave::deref (this=0xa33b0d0) at /build/buildd/kde4libs-4.3.1/kio/kio/slave.cpp:242
#7  0xb6c2db3c in KIO::Slave::gotInput (this=0xa33b0d0) at /build/buildd/kde4libs-4.3.1/kio/kio/slave.cpp:335
#8  0xb6c2ffc3 in KIO::Slave::qt_metacall (this=0xa33b0d0, _c=QMetaObject::InvokeMetaMethod, _id=2, _a=0xbfe21e18) at /build/buildd/kde4libs-4.3.1/obj-i486-linux-gnu/kio/slave.moc:76
#9  0xb5e041b8 in QMetaObject::activate (sender=0xa431250, from_signal_index=4, to_signal_index=4, argv=0x0) at kernel/qobject.cpp:3113
#10 0xb5e04e42 in QMetaObject::activate (sender=0xa431250, m=0xb6d1b880, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3187
#11 0xb6b39697 in KIO::Connection::readyRead (this=0xa431250) at /build/buildd/kde4libs-4.3.1/obj-i486-linux-gnu/kio/connection.moc:86
#12 0xb6b3b003 in KIO::ConnectionPrivate::dequeue (this=0xa32d6a0) at /build/buildd/kde4libs-4.3.1/kio/kio/connection.cpp:82
#13 0xb6b3b3e6 in KIO::Connection::qt_metacall (this=0xa431250, _c=QMetaObject::InvokeMetaMethod, _id=1, _a=0xac7aa68) at /build/buildd/kde4libs-4.3.1/obj-i486-linux-gnu/kio/connection.moc:73
#14 0xb5dfd8cb in QMetaCallEvent::placeMetaCall (this=0xbcba3a8, object=0xa431250) at kernel/qobject.cpp:477
#15 0xb5dff3b0 in QObject::event (this=0xa431250, e=0xbcba3a8) at kernel/qobject.cpp:1111
#16 0xb607ad3c in QApplicationPrivate::notify_helper (this=0x90f86a0, receiver=0xa431250, e=0xbcba3a8) at kernel/qapplication.cpp:4056
#17 0xb608303e in QApplication::notify (this=0xbfe22648, receiver=0xa431250, e=0xbcba3a8) at kernel/qapplication.cpp:3603
#18 0xb7d9685d in KApplication::notify (this=0xbfe22648, receiver=0xa431250, event=0xbcba3a8) at /build/buildd/kde4libs-4.3.1/kdeui/kernel/kapplication.cpp:302
#19 0xb5deebcb in QCoreApplication::notifyInternal (this=0xbfe22648, receiver=0xa431250, event=0xbcba3a8) at kernel/qcoreapplication.cpp:610
#20 0xb5def825 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x90ce1f0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#21 0xb5defa1d in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1140
#22 0xb5e1a6af in postEventSourceDispatch (s=0x9303b38) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#23 0xb41f0b88 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#24 0xb41f40eb in ?? () from /usr/lib/libglib-2.0.so.0
#25 0xb41f4268 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#26 0xb5e1a2f8 in QEventDispatcherGlib::processEvents (this=0x90ce3c8, flags={i = -1075698520}) at kernel/qeventdispatcher_glib.cpp:327
#27 0xb611ca75 in QGuiEventDispatcherGlib::processEvents (this=0x90ce3c8, flags={i = -1075698472}) at kernel/qguieventdispatcher_glib.cpp:202
#28 0xb5ded1fa in QEventLoop::processEvents (this=0xbfe22550, flags={i = -1075698408}) at kernel/qeventloop.cpp:149
#29 0xb5ded642 in QEventLoop::exec (this=0xbfe22550, flags={i = -1075698344}) at kernel/qeventloop.cpp:201
#30 0xb5defae9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#31 0xb607abb7 in QApplication::exec () at kernel/qapplication.cpp:3525
#32 0x0804a7d0 in main (argc=136, argv=0xb8) at /build/buildd/kdepim-4.3.1/kmail/main.cpp:146

Reported using DrKonqi