Application that crashed: kontact
Version of the application: 4.3.5
KDE Version: 4.3.5 (KDE 4.3.5)
Qt Version: 4.6.2
Operating System: Linux 2.6.32-gentoo-r7 x86_64

What I was doing when the application crashed:
During normal operation in Kontact, I managed to click a folder (marked as favorite, also on the summary page) and bang! Crash!

After restart clicking that folder again crashes.

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
Traceback (most recent call last):
  File "/usr/share/gdb/auto-load/usr/lib64/libgobject-2.0.so.0.2200.5-gdb.py", line 9, in <module>
    from gobject import register
  File "/usr/share/glib-2.0/gdb/gobject.py", line 3, in <module>
    import gdb.backtrace
ImportError: No module named backtrace
[Current thread is 1 (Thread 0x7fd367ef4740 (LWP 8916))]

Thread 3 (Thread 0x7fd349c73910 (LWP 8920)):
#0  0x00007fd36136e3fd in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007fd3615f92c7 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib64/qt4/libQtCore.so.4
#2  0x00007fd3615eeacb in ?? () from /usr/lib64/qt4/libQtCore.so.4
#3  0x00007fd3615f84a1 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#4  0x00007fd36136a287 in start_thread () from /lib/libpthread.so.0
#5  0x00007fd3609406ad in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7fd34926c910 (LWP 8925)):
#0  0x00007fd36136e3fd in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007fd3615f92c7 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib64/qt4/libQtCore.so.4
#2  0x00007fd3615eeacb in ?? () from /usr/lib64/qt4/libQtCore.so.4
#3  0x00007fd3615f84a1 in ?? () from /usr/lib64/qt4/libQtCore.so.4
#4  0x00007fd36136a287 in start_thread () from /lib/libpthread.so.0
#5  0x00007fd3609406ad in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fd367ef4740 (LWP 8916)):
[KCrash Handler]
#5  0x00007fd36170e5d4 in QMetaObject::addGuard(QObject**) () from /usr/lib64/qt4/libQtCore.so.4
#6  0x00007fd362559485 in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/qt4/libQtGui.so.4
#7  0x00007fd363506a16 in KApplication::notify(QObject*, QEvent*) () from /usr/lib64/libkdeui.so.5
#8  0x00007fd3616fa348 in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib64/qt4/libQtCore.so.4
#9  0x00007fd362563623 in QApplicationPrivate::sendMouseEvent(QWidget*, QMouseEvent*, QWidget*, QWidget*, QWidget**, QPointer<QWidget>&, bool) () from /usr/lib64/qt4/libQtGui.so.4
#10 0x00007fd3625e0691 in ?? () from /usr/lib64/qt4/libQtGui.so.4
#11 0x00007fd3625df0e7 in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib64/qt4/libQtGui.so.4
#12 0x00007fd362608e36 in ?? () from /usr/lib64/qt4/libQtGui.so.4
#13 0x00007fd35d54a533 in ?? () from /usr/lib/libglib-2.0.so.0
#14 0x00007fd35d54c07a in ?? () from /usr/lib/libglib-2.0.so.0
#15 0x00007fd35d54c1cb in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#16 0x00007fd361724e74 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#17 0x00007fd362608826 in ?? () from /usr/lib64/qt4/libQtGui.so.4
#18 0x00007fd3616f92a4 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#19 0x00007fd3616f95ef in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/qt4/libQtCore.so.4
#20 0x00007fd3616fb6d8 in QCoreApplication::exec() () from /usr/lib64/qt4/libQtCore.so.4
#21 0x0000000000404c47 in _start ()

Reported using DrKonqi