Version:            (using KDE 4.2.0)
Compiler:          gcc (SUSE Linux) 4.3.2 [gcc-4_3-branch revision 141291] 
OS:                Linux
Installed from:    SuSE RPMs

Kontact crashed once when deleting e-mails, here's the backtrace:

Application: Kontact (kontact), signal SIGSEGV
[?1034h[Thread debugging using libthread_db enabled]
[Current thread is 1 (Thread 0xb4a16700 (LWP 6627))]

Thread 2 (Thread 0xafccdb90 (LWP 6643)):
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb5ab73e1 in select () from /lib/libc.so.6
#2  0xb67dbdc7 in QProcessManager::run (this=0x80744d8) at io/qprocess_unix.cpp:301
#3  0xb670c85e in QThreadPrivate::start (arg=0x80744d8) at thread/qthread_unix.cpp:185
#4  0xb66a91b5 in start_thread () from /lib/libpthread.so.0
#5  0xb5abe38e in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb4a16700 (LWP 6627)):
[KCrash Handler]
#6  KMMoveCommand (this=0x9699560, destFolder=0x85b3570, msgList=@0xbfdca978) at /usr/src/debug/kdepim-4.2.0/kmail/kmcommands.cpp:2001
#7  0xb112dacb in KMDeleteMsgCommand (this=0x9699560, srcFolder=0x85338b0, msgList=@0xbfdca978) at /usr/src/debug/kdepim-4.2.0/kmail/kmcommands.cpp:2229
#8  0xb116552f in KMMainWidget::trashMessageSet (this=0x85e1230, set=0x8c08170) at /usr/src/debug/kdepim-4.2.0/kmail/kmmainwidget.cpp:2005
#9  0xb1165708 in KMMainWidget::slotTrashThread (this=0x85e1230) at /usr/src/debug/kdepim-4.2.0/kmail/kmmainwidget.cpp:2072
#10 0xb1178e9a in KMMainWidget::qt_metacall (this=0x85e1230, _c=QMetaObject::InvokeMetaMethod, _id=67, _a=0xbfdcaacc) at /usr/src/debug/kdepim-4.2.0/build/kmail/kmmainwidget.moc:411
#11 0xb6811580 in QMetaObject::activate (sender=0x86b7128, from_signal_index=5, to_signal_index=6, argv=0xbfdcaacc) at kernel/qobject.cpp:3031
#12 0xb6811980 in QMetaObject::activate (sender=0x86b7128, m=0xb6546c78, from_local_signal_index=1, to_local_signal_index=2, argv=0xbfdcaacc) at kernel/qobject.cpp:3121
#13 0xb5d8b631 in QAction::triggered (this=0x86b7128, _t1=false) at .moc/release-shared/moc_qaction.cpp:216
#14 0xb5d8bf9f in QAction::activate (this=0x86b7128, event=QAction::Trigger) at kernel/qaction.cpp:1125
#15 0xb5d8f4cb in QAction::event (this=0x86b7128, e=0xbfdcaf04) at kernel/qaction.cpp:1044
#16 0xb6cc20c9 in KAction::event (this=0x86b7128, event=0xbfdcaf04) at /usr/src/debug/kdelibs-4.2.0/kdeui/actions/kaction.cpp:88
#17 0xb5d918fc in QApplicationPrivate::notify_helper (this=0x806fae8, receiver=0x86b7128, e=0xbfdcaf04) at kernel/qapplication.cpp:3803
#18 0xb5d9975e in QApplication::notify (this=0xbfdcbd08, receiver=0x86b7128, e=0xbfdcaf04) at kernel/qapplication.cpp:3393
#19 0xb6d9c91d in KApplication::notify (this=0xbfdcbd08, receiver=0x86b7128, event=0xbfdcaf04) at /usr/src/debug/kdelibs-4.2.0/kdeui/kernel/kapplication.cpp:307
#20 0xb67fc961 in QCoreApplication::notifyInternal (this=0xbfdcbd08, receiver=0x86b7128, event=0xbfdcaf04) at kernel/qcoreapplication.cpp:587
#21 0xb5dca9b8 in QShortcutMap::dispatchEvent (this=0x806fb84, e=0xbfdcb29c) at ../../src/corelib/kernel/qcoreapplication.h:209
#22 0xb5dcc3ff in QShortcutMap::tryShortcutEvent (this=0x806fb84, w=0x85f1018, e=0xbfdcb29c) at kernel/qshortcutmap.cpp:362
#23 0xb5d9aa20 in QApplication::notify (this=0xbfdcbd08, receiver=0x85f1018, e=0xbfdcb29c) at kernel/qapplication.cpp:3430
#24 0xb6d9c91d in KApplication::notify (this=0xbfdcbd08, receiver=0x85f1018, event=0xbfdcb29c) at /usr/src/debug/kdelibs-4.2.0/kdeui/kernel/kapplication.cpp:307
#25 0xb67fc961 in QCoreApplication::notifyInternal (this=0xbfdcbd08, receiver=0x85f1018, event=0xbfdcb29c) at kernel/qcoreapplication.cpp:587
#26 0xb5df24be in qt_sendSpontaneousEvent (receiver=0x85f1018, event=0xa13a51c) at ../../src/corelib/kernel/qcoreapplication.h:212
#27 0xb5e27470 in QKeyMapper::sendKeyEvent (keyWidget=0x85f1018, grab=false, type=QEvent::KeyPress, code=16777223, modifiers={i = -1076055064}, text=@0xbfdcb414, autorepeat=<value optimized out>, 
    count=<value optimized out>, nativeScanCode=107, nativeVirtualKey=65535, nativeModifiers=20) at kernel/qkeymapper_x11.cpp:1655
#28 0xb5e29606 in QKeyMapperPrivate::translateKeyEvent (this=0x80a0d70, keyWidget=0x85f1018, event=0xbfdcba1c, grab=false) at kernel/qkeymapper_x11.cpp:1626
#29 0xb5e01bd5 in QApplication::x11ProcessEvent (this=0xbfdcbd08, event=0xbfdcba1c) at kernel/qapplication_x11.cpp:3051
#30 0xb5e2b08a in x11EventSourceDispatch (s=0x8073eb8, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:142
#31 0xb51a49a8 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#32 0xb51a8063 in ?? () from /usr/lib/libglib-2.0.so.0
#33 0xb51a8221 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#34 0xb6826fb8 in QEventDispatcherGlib::processEvents (this=0x806b3c8, flags={i = -1076053032}) at kernel/qeventdispatcher_glib.cpp:319
#35 0xb5e2a785 in QGuiEventDispatcherGlib::processEvents (this=0x806b3c8, flags={i = -1076052984}) at kernel/qguieventdispatcher_glib.cpp:198
#36 0xb67fb01a in QEventLoop::processEvents (this=0xbfdcbc80, flags={i = -1076052920}) at kernel/qeventloop.cpp:143
#37 0xb67fb1da in QEventLoop::exec (this=0xbfdcbc80, flags={i = -1076052856}) at kernel/qeventloop.cpp:194
#38 0xb67fd895 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845
#39 0xb5d91777 in QApplication::exec () at kernel/qapplication.cpp:3331
#40 0x0804bf8f in main (argc=1, argv=0xbfdcc004) at /usr/src/debug/kdepim-4.2.0/kontact/src/main.cpp:218