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 2.6.28-15-generic x86_64
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
I had two dimap accounts configured in kmail and removed one of the accounts.
In the background the interval mail check was triggered and kmail conplained about missing files and folder for the removed dimap account. After several of these warning dialogs kmail crashed with the attached backtrace.

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#5  0x00007f0ca02f6e16 in KMFolderCachedImap::slotListResult (this=0x3c633c0, folderNames=@0x3f4dd28, folderPaths=@0x3f4dd30, folderMimeTypes=@0x3f4dd38, folderAttributes=@0x3f4dd40, 
    jobData=@0x3750f18) at /usr/include/qt4/QtCore/qlist.h:90
#6  0x00007f0ca0301b84 in KMFolderCachedImap::qt_metacall (this=0x3c633c0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fffc0a10ae0)
    at /build/buildd/kdepim-4.3.1/obj-x86_64-linux-gnu/kmail/kmfoldercachedimap.moc:226
#7  0x00007f0cb2f62ea2 in QMetaObject::activate (sender=0x3f4dcc0, from_signal_index=<value optimized out>, to_signal_index=12, argv=0x0) at kernel/qobject.cpp:3113
#8  0x00007f0ca01bef02 in KMail::ListJob::receivedFolders (this=0x3f4dcc0, _t1=<value optimized out>, _t2=<value optimized out>, _t3=@0x3f4dd38, _t4=@0x3aec2b0, _t5=@0x7f0ca92e4782)
    at /build/buildd/kdepim-4.3.1/obj-x86_64-linux-gnu/kmail/listjob.moc:91
#9  0x00007f0ca01bfe5b in KMail::ListJob::slotListResult (this=0x3f4dcc0, job=0x3ba9d70) at /build/buildd/kdepim-4.3.1/kmail/listjob.cpp:181
#10 0x00007f0ca01c11e7 in KMail::ListJob::qt_metacall (this=0x3f4dcc0, _c=QMetaObject::InvokeMetaMethod, _id=1, _a=0x7fffc0a10d80)
    at /build/buildd/kdepim-4.3.1/obj-x86_64-linux-gnu/kmail/listjob.moc:77
#11 0x00007f0cb2f62ea2 in QMetaObject::activate (sender=0x3ba9d70, from_signal_index=<value optimized out>, to_signal_index=7, argv=0x0) at kernel/qobject.cpp:3113
#12 0x00007f0cb35a1942 in KJob::result (this=0x2a33090, _t1=0x3ba9d70) at /build/buildd/kde4libs-4.3.1/obj-x86_64-linux-gnu/kdecore/kjob.moc:188
#13 0x00007f0cb35a1cbf in KJob::emitResult (this=0x3ba9d70) at /build/buildd/kde4libs-4.3.1/kdecore/jobs/kjob.cpp:304
#14 0x00007f0cb53b9210 in KIO::SimpleJob::slotFinished (this=0x3ba9d70) at /build/buildd/kde4libs-4.3.1/kio/kio/job.cpp:477
#15 0x00007f0cb53b9345 in KIO::ListJob::slotFinished (this=0x3ba9d70) at /build/buildd/kde4libs-4.3.1/kio/kio/job.cpp:2408
#16 0x00007f0cb53b649d in KIO::ListJob::qt_metacall (this=0x3ba9d70, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fffc0a110c0)
    at /build/buildd/kde4libs-4.3.1/obj-x86_64-linux-gnu/kio/jobclasses.moc:764
#17 0x00007f0cb2f62ea2 in QMetaObject::activate (sender=0x3eb75c0, from_signal_index=<value optimized out>, to_signal_index=8, argv=0x0) at kernel/qobject.cpp:3113
#18 0x00007f0cb5475891 in KIO::SlaveInterface::dispatch (this=0x3eb75c0, _cmd=104, rawdata=<value optimized out>) at /build/buildd/kde4libs-4.3.1/kio/kio/slaveinterface.cpp:175
#19 0x00007f0cb54723e2 in KIO::SlaveInterface::dispatch (this=0x3eb75c0) at /build/buildd/kde4libs-4.3.1/kio/kio/slaveinterface.cpp:91
#20 0x00007f0cb5464f63 in KIO::Slave::gotInput (this=0x3eb75c0) at /build/buildd/kde4libs-4.3.1/kio/kio/slave.cpp:322
#21 0x00007f0cb54671c8 in KIO::Slave::qt_metacall (this=0x3eb75c0, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0x7fffc0a114e0) at /build/buildd/kde4libs-4.3.1/obj-x86_64-linux-gnu/kio/slave.moc:76
#22 0x00007f0cb2f62ea2 in QMetaObject::activate (sender=0x3eefda0, from_signal_index=<value optimized out>, to_signal_index=4, argv=0x0) at kernel/qobject.cpp:3113
#23 0x00007f0cb5381db1 in KIO::ConnectionPrivate::dequeue (this=0x44bc560) at /build/buildd/kde4libs-4.3.1/kio/kio/connection.cpp:82
#24 0x00007f0cb538220a in KIO::Connection::qt_metacall (this=0x3eefda0, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0x371b260)
    at /build/buildd/kde4libs-4.3.1/obj-x86_64-linux-gnu/kio/connection.moc:73
#25 0x00007f0cb2f5d5d8 in QObject::event (this=0x3eefda0, e=0x3b9a610) at kernel/qobject.cpp:1111
#26 0x00007f0cb3acdf4d in QApplicationPrivate::notify_helper (this=0x1fc1930, receiver=0x3eefda0, e=0x3b9a610) at kernel/qapplication.cpp:4056
#27 0x00007f0cb3ad618a in QApplication::notify (this=0x7fffc0a11f40, receiver=0x3eefda0, e=0x3b9a610) at kernel/qapplication.cpp:4021
#28 0x00007f0cb4ed2deb in KApplication::notify (this=0x7fffc0a11f40, receiver=0x3eefda0, event=0x3b9a610) at /build/buildd/kde4libs-4.3.1/kdeui/kernel/kapplication.cpp:302
#29 0x00007f0cb2f4d6ac in QCoreApplication::notifyInternal (this=0x7fffc0a11f40, receiver=0x3eefda0, event=0x3b9a610) at kernel/qcoreapplication.cpp:610
#30 0x00007f0cb2f4e31a in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x1f80850) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#31 0x00007f0cb2f76e03 in postEventSourceDispatch (s=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#32 0x00007f0cac69d20a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#33 0x00007f0cac6a08e0 in ?? () from /usr/lib/libglib-2.0.so.0
#34 0x00007f0cac6a0a7c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#35 0x00007f0cb2f76a8f in QEventDispatcherGlib::processEvents (this=0x1f800a0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#36 0x00007f0cb3b66bdf in QGuiEventDispatcherGlib::processEvents (this=0x2a33090, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#37 0x00007f0cb2f4bf42 in QEventLoop::processEvents (this=<value optimized out>, flags={i = -1063182752}) at kernel/qeventloop.cpp:149
#38 0x00007f0cb2f4c314 in QEventLoop::exec (this=0x7fffc0a11ea0, flags={i = -1063182672}) at kernel/qeventloop.cpp:201
#39 0x00007f0cb2f4e5e4 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#40 0x0000000000404945 in main (argc=3, argv=0x7fffc0a12628) at /build/buildd/kdepim-4.3.1/kontact/src/main.cpp:218

Reported using DrKonqi