Application that crashed: kmail
Version of the application: 1.12.3
KDE Version: 4.3.3 (KDE 4.3.3)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-15-generic x86_64
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
While reading the emails, and tried to open an attachment (the type does not really matter), KMail crashes.
Sometimes I've noticed, that it happens more often if the mail is not fully downloaded.

IMAP + TLS (SSL) on GMAIL.

 -- Backtrace:
Application: KMail (kmail), signal: Segmentation fault
[KCrash Handler]
#5  0x00007f1437048c12 in KMLoadPartsCommand::slotPartRetrieved(KMMessage*, QString const&) () from /usr/lib/libkmailprivate.so.4
#6  0x00007f143704a8a6 in KMLoadPartsCommand::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkmailprivate.so.4
#7  0x00007f1435ae4ddc in QMetaObject::activate (sender=0x3398c90, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x0) at kernel/qobject.cpp:3113
#8  0x00007f1437097f77 in ?? () from /usr/lib/libkmailprivate.so.4
#9  0x00007f14370a3ece in ?? () from /usr/lib/libkmailprivate.so.4
#10 0x00007f14370a825b in ?? () from /usr/lib/libkmailprivate.so.4
#11 0x00007f1435ae4ddc in QMetaObject::activate (sender=0x29c70f0, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x0) at kernel/qobject.cpp:3113
#12 0x00007f143776db22 in KJob::result (this=0x3398cc8, _t1=0x29c70f0) at ./kjob.moc:188
#13 0x00007f143776de9f in KJob::emitResult (this=0x29c70f0) at ../../kdecore/jobs/kjob.cpp:304
#14 0x00007f142f88ee33 in KIO::SimpleJob::slotFinished (this=0x29c70f0) at ../../kio/kio/job.cpp:477
#15 0x00007f142f88f2f3 in KIO::TransferJob::slotFinished (this=0x29c70f0) at ../../kio/kio/job.cpp:948
#16 0x00007f142f88dc01 in KIO::TransferJob::qt_metacall (this=0x29c70f0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff6a2107a0) at ./jobclasses.moc:343
#17 0x00007f1435ae4ddc in QMetaObject::activate (sender=0x29d21e0, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x0) at kernel/qobject.cpp:3113
#18 0x00007f142f94fb31 in KIO::SlaveInterface::dispatch (this=0x29d21e0, _cmd=104, rawdata=...) at ../../kio/kio/slaveinterface.cpp:175
#19 0x00007f142f94c3e3 in KIO::SlaveInterface::dispatch (this=0x29d21e0) at ../../kio/kio/slaveinterface.cpp:91
#20 0x00007f142f93f1fd in KIO::Slave::gotInput (this=0x29d21e0) at ../../kio/kio/slave.cpp:322
#21 0x00007f142f94131c in KIO::Slave::qt_metacall (this=0x29d21e0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff6a210b60) at ./slave.moc:76
#22 0x00007f1435ae4ddc in QMetaObject::activate (sender=0x29d3b40, from_signal_index=<value optimized out>, to_signal_index=<value optimized out>, argv=0x0) at kernel/qobject.cpp:3113
#23 0x00007f142f85bf77 in KIO::ConnectionPrivate::dequeue (this=0x22b29b0) at ../../kio/kio/connection.cpp:82
#24 0x00007f142f85c09d in KIO::Connection::qt_metacall (this=0x29d3b40, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x20d18c0) at ./connection.moc:73
#25 0x00007f1435adf0f9 in QObject::event (this=0x29d3b40, e=0x2d0f770) at kernel/qobject.cpp:1111
#26 0x00007f1435f62efc in QApplicationPrivate::notify_helper (this=0x1f66a10, receiver=0x29d3b40, e=0x2d0f770) at kernel/qapplication.cpp:4056
#27 0x00007f1435f6a1ce in QApplication::notify (this=0x7fff6a211630, receiver=0x29d3b40, e=0x2d0f770) at kernel/qapplication.cpp:4021
#28 0x00007f1437d25e56 in KApplication::notify (this=0x7fff6a211630, receiver=0x29d3b40, event=0x2d0f770) at ../../kdeui/kernel/kapplication.cpp:302
#29 0x00007f1435acfc2c in QCoreApplication::notifyInternal (this=0x7fff6a211630, receiver=0x29d3b40, event=0x2d0f770) at kernel/qcoreapplication.cpp:610
#30 0x00007f1435ad080a in QCoreApplication::sendEvent (receiver=0x0, event_type=<value optimized out>, data=0x1f2bd00) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#31 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=<value optimized out>, data=0x1f2bd00) at kernel/qcoreapplication.cpp:1247
#32 0x00007f1435af8533 in QCoreApplication::sendPostedEvents (s=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#33 postEventSourceDispatch (s=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:210
#34 0x00007f142cd69bbe in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#35 0x00007f142cd6d588 in ?? () from /lib/libglib-2.0.so.0
#36 0x00007f142cd6d6b0 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#37 0x00007f1435af81a6 in QEventDispatcherGlib::processEvents (this=0x1f2b930, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#38 0x00007f1435ff74be in QGuiEventDispatcherGlib::processEvents (this=0x3398cc8, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#39 0x00007f1435ace532 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#40 0x00007f1435ace904 in QEventLoop::exec (this=0x7fff6a211460, flags=) at kernel/qeventloop.cpp:201
#41 0x00007f1435ad0ab9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#42 0x0000000000402fe9 in _start ()

Reported using DrKonqi