Application that crashed: kontact
Version of the application: 4.3.1
KDE Version: 4.3.1 (KDE 4.3.1)
Qt Version: 4.5.2
Operating System: Linux 2.6.30-1-686 i686
Distribution: Debian GNU/Linux testing (squeeze)

What I was doing when the application crashed:
I imported mails from an external mbox file. That worked without problem. Then I chose the imported folder in Inbox and clicked on the first message in the imported folder. Then Kontact/Kmail crashed.

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#6  0x0a3e1bb3 in ?? ()
#7  0xb0e43a0b in KMReaderWin::displayMessage (this=0x99406a1) at ../../kmail/kmreaderwin.cpp:1605
#8  0xb0e43c20 in KMReaderWin::updateReaderWin (this=0x9857788) at ../../kmail/kmreaderwin.cpp:1545
#9  0xb0e50647 in KMReaderWin::qt_metacall (this=0x9857788, _c=QMetaObject::InvokeMetaMethod, _id=6, _a=0xbfc49708) at ./kmreaderwin.moc:168
#10 0xb76e0b33 in QMetaObject::activate (sender=0x98577e0, from_signal_index=4, to_signal_index=4, argv=0x0) at kernel/qobject.cpp:3112
#11 0xb76e1782 in QMetaObject::activate (sender=0x98577e0, m=0xb77bcde4, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3186
#12 0xb771c177 in QTimer::timeout (this=0x98577e0) at .moc/release-shared/moc_qtimer.cpp:128
#13 0xb76e6e9e in QTimer::timerEvent (this=0x98577e0, e=0xbfc49b8c) at kernel/qtimer.cpp:261
#14 0xb76dbbcf in QObject::event (this=0x98577e0, e=0xbfc49b8c) at kernel/qobject.cpp:1074
#15 0xb6d0b814 in QApplicationPrivate::notify_helper (this=0x9373f18, receiver=0x98577e0, e=0xbfc49b8c) at kernel/qapplication.cpp:4056
#16 0xb6d1397e in QApplication::notify (this=0xbfc49f3c, receiver=0x98577e0, e=0xbfc49b8c) at kernel/qapplication.cpp:3603
#17 0xb7bcc4ad in KApplication::notify (this=0xbfc49f3c, receiver=0x98577e0, event=0xbfc49b8c) at ../../kdeui/kernel/kapplication.cpp:302
#18 0xb76cb9cb in QCoreApplication::notifyInternal (this=0xbfc49f3c, receiver=0x98577e0, event=0xbfc49b8c) at kernel/qcoreapplication.cpp:610
#19 0xb76fa361 in QCoreApplication::sendEvent (this=0x936be5c) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#20 QTimerInfoList::activateTimers (this=0x936be5c) at kernel/qeventdispatcher_unix.cpp:572
#21 0xb76f6900 in timerSourceDispatch (source=0x936be28) at kernel/qeventdispatcher_glib.cpp:165
#22 0xb5127e98 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#23 0xb512b623 in ?? () from /lib/libglib-2.0.so.0
#24 0xb512b7a8 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#25 0xb76f6858 in QEventDispatcherGlib::processEvents (this=0x934c700, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#26 0xb6daafd5 in QGuiEventDispatcherGlib::processEvents (this=0x934c700, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#27 0xb76ca01a in QEventLoop::processEvents (this=0xbfc49db0, flags=...) at kernel/qeventloop.cpp:149
#28 0xb76ca462 in QEventLoop::exec (this=0xbfc49db0, flags=...) at kernel/qeventloop.cpp:201
#29 0xb76cc8b9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#30 0xb6d0b697 in QApplication::exec () at kernel/qapplication.cpp:3525
#31 0x0804bd40 in main (argc=1, argv=0xbfc4a134) at ../../../kontact/src/main.cpp:218

Reported using DrKonqi