Application: kontact (4.4.2)
KDE Platform Version: 4.4.2 (KDE 4.4.2)
Qt Version: 4.6.2
Operating System: Linux 2.6.33.3-85.fc13.x86_64 x86_64
Distribution (Platform): Fedora RPMs

-- Information about the crash:
I had been going through each section of the settings and applying before moving onto the next section when this occurred. I clicked the icon again after kontact started up again and it worked fine.

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
82	T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
[KCrash Handler]
#5  size (this=<value optimized out>) at ../../src/corelib/tools/qlist.h:90
#6  count (this=<value optimized out>) at ../../src/corelib/tools/qlist.h:261
#7  childCount (this=<value optimized out>) at itemviews/qtreewidget.h:190
#8  QTreeWidget::topLevelItemCount (this=<value optimized out>) at itemviews/qtreewidget.cpp:2608
#9  0x0000003de0c0c784 in KMail::FolderSelectionTreeWidget::reload (this=0x2120590, mustBeReadWrite=<value optimized out>, showOutbox=<value optimized out>, showImapFolders=<value optimized out>, 
    preSelection=...) at /usr/src/debug/kdepim-4.4.2/kmail/folderselectiontreewidget.cpp:177
#10 0x0000003de0c0d4ff in KMail::FolderSelectionDialog::init (this=0x20a50b0, tree=<value optimized out>, mustBeReadWrite=<value optimized out>)
    at /usr/src/debug/kdepim-4.4.2/kmail/folderselectiondialog.cpp:70
#11 0x0000003de0c0d7be in KMail::FolderSelectionDialog::FolderSelectionDialog (this=0x20a50b0, parent=<value optimized out>, tree=0xd60500, caption=..., mustBeReadWrite=true, 
    useGlobalSettings=<value optimized out>) at /usr/src/debug/kdepim-4.4.2/kmail/folderselectiondialog.cpp:53
#12 0x0000003de0e09f69 in KMail::FolderRequester::slotOpenDialog (this=0x1bf6710) at /usr/src/debug/kdepim-4.4.2/kmail/folderrequester.cpp:83
#13 0x0000003de0e0a0e1 in KMail::FolderRequester::qt_metacall (this=0x1bf6710, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff47c01c60)
    at /usr/src/debug/kdepim-4.4.2/x86_64-redhat-linux-gnu/kmail/folderrequester.moc:77
#14 0x0000003dc6d6a81f in QMetaObject::activate (sender=0x1bf7f50, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x7fff47c01c60) at kernel/qobject.cpp:3293
#15 0x0000003dca7df812 in QAbstractButton::clicked (this=<value optimized out>, _t1=false) at .moc/release-shared/moc_qabstractbutton.cpp:206
#16 0x0000003dca52efcb in QAbstractButtonPrivate::emitClicked (this=<value optimized out>) at widgets/qabstractbutton.cpp:546
#17 0x0000003dca53034b in QAbstractButtonPrivate::click (this=0x1bf8830) at widgets/qabstractbutton.cpp:539
#18 0x0000003dca5305bc in QAbstractButton::mouseReleaseEvent (this=0x1bf7f50, e=0x7fff47c025c0) at widgets/qabstractbutton.cpp:1121
#19 0x0000003dca5eb33a in QToolButton::mouseReleaseEvent (this=<value optimized out>, e=<value optimized out>) at widgets/qtoolbutton.cpp:721
#20 0x0000003dca1f5aba in QWidget::event (this=0x1bf7f50, event=0x7fff47c025c0) at kernel/qwidget.cpp:7998
#21 0x0000003dca1aaa0c in QApplicationPrivate::notify_helper (this=0x761890, receiver=0x1bf7f50, e=0x7fff47c025c0) at kernel/qapplication.cpp:4300
#22 0x0000003dca1b11ad in QApplication::notify (this=<value optimized out>, receiver=0x1bf7f50, e=0x7fff47c025c0) at kernel/qapplication.cpp:3865
#23 0x0000003dcbc06da6 in KApplication::notify (this=0x7fff47c032d0, receiver=0x1bf7f50, event=0x7fff47c025c0) at /usr/src/debug/kdelibs-4.4.2/kdeui/kernel/kapplication.cpp:302
#24 0x0000003dc6d57cdc in QCoreApplication::notifyInternal (this=0x7fff47c032d0, receiver=0x1bf7f50, event=0x7fff47c025c0) at kernel/qcoreapplication.cpp:704
#25 0x0000003dca1b039e in sendEvent (receiver=0x1bf7f50, event=0x7fff47c025c0, alienWidget=0x1bf7f50, nativeWidget=0x1bec780, buttonDown=0x3dcac2b108, lastMouseReceiver=..., spontaneous=true)
    at ../../src/corelib/kernel/qcoreapplication.h:215
#26 QApplicationPrivate::sendMouseEvent (receiver=0x1bf7f50, event=0x7fff47c025c0, alienWidget=0x1bf7f50, nativeWidget=0x1bec780, buttonDown=0x3dcac2b108, lastMouseReceiver=..., spontaneous=true)
    at kernel/qapplication.cpp:2965
#27 0x0000003dca2223c5 in QETWidget::translateMouseEvent (this=0x1bec780, event=<value optimized out>) at kernel/qapplication_x11.cpp:4373
#28 0x0000003dca220d3c in QApplication::x11ProcessEvent (this=0x7fff47c032d0, event=0x7fff47c02ee0) at kernel/qapplication_x11.cpp:3506
#29 0x0000003dca249d12 in x11EventSourceDispatch (s=0x767830, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#30 0x0000003dbf43bd02 in g_main_dispatch (context=0x764920) at gmain.c:1960
#31 IA__g_main_context_dispatch (context=0x764920) at gmain.c:2513
#32 0x0000003dbf43fae8 in g_main_context_iterate (context=0x764920, block=1, dispatch=1, self=<value optimized out>) at gmain.c:2591
#33 0x0000003dbf43fc9c in IA__g_main_context_iteration (context=0x764920, may_block=1) at gmain.c:2654
#34 0x0000003dc6d7d603 in QEventDispatcherGlib::processEvents (this=0x736460, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:412
#35 0x0000003dca2499de in QGuiEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#36 0x0000003dc6d56722 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#37 0x0000003dc6d569ec in QEventLoop::exec (this=0x7fff47c03210, flags=...) at kernel/qeventloop.cpp:201
#38 0x0000003dc6d58cd9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:981
#39 0x0000000000403cae in main (argc=<value optimized out>, argv=<value optimized out>) at /usr/src/debug/kdepim-4.4.2/kontact/src/main.cpp:224

Reported using DrKonqi