Application that crashed: kontact
Version of the application: 4.3.0
KDE Version: 4.3.00 (KDE 4.3.0)
Qt Version: 4.5.2
Operating System: Linux 2.6.30-ARCH x86_64
Distribution: "(none)"

What I was doing when the application crashed:
When I login in, I get a message about starting Kontanct. And then I get two instances. On close of each instance, I get this crash. 

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[Current thread is 0 (LWP 4186)]

Thread 3 (Thread 0x7fd97e502910 (LWP 4409)):
#0  0x00007fd99587105d in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007fd99a2e52b2 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#2  0x00007fd99a2db412 in ?? () from /usr/lib/libQtCore.so.4
#3  0x00007fd99a2e4285 in ?? () from /usr/lib/libQtCore.so.4
#4  0x00007fd99586c57a in start_thread () from /lib/libpthread.so.0
#5  0x00007fd99914016d in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7fd97dafb910 (LWP 4410)):
#0  0x00007fd99587105d in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007fd99a2e52b2 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#2  0x00007fd99a2db412 in ?? () from /usr/lib/libQtCore.so.4
#3  0x00007fd99a2e4285 in ?? () from /usr/lib/libQtCore.so.4
#4  0x00007fd99586c57a in start_thread () from /lib/libpthread.so.0
#5  0x00007fd99914016d in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fd99bab3760 (LWP 4186)):
[KCrash Handler]
#5  0x00007fd984ba2ce1 in KMMainWidget::initializeFilterActions () from /usr/lib/libkmailprivate.so.4
#6  0x00007fd9851a8b76 in KMailPart::guiActivateEvent () from /usr/lib/kde4/kmailpart.so
#7  0x00007fd99a3d9185 in QObject::event () from /usr/lib/libQtCore.so.4
#8  0x00007fd999875e2c in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#9  0x00007fd99987d0fe in QApplication::notify () from /usr/lib/libQtGui.so.4
#10 0x00007fd99ad66ff6 in KApplication::notify () from /usr/lib/libkdeui.so.5
#11 0x00007fd99a3c9d0c in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#12 0x00007fd998e57507 in KParts::MainWindow::createGUI () from /usr/lib/libkparts.so.4
#13 0x00007fd99b6d885d in Kontact::MainWindow::selectPlugin () from /usr/lib/libkontactprivate.so.4
#14 0x00007fd99b6dd022 in Kontact::MainWindow::qt_metacall () from /usr/lib/libkontactprivate.so.4
#15 0x00007fd99a3dee0c in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#16 0x00007fd99b6de1bf in Kontact::SidePaneBase::pluginSelected () from /usr/lib/libkontactprivate.so.4
#17 0x00007fd99b6de210 in Kontact::SidePaneBase::qt_metacall () from /usr/lib/libkontactprivate.so.4
#18 0x00007fd99b6de408 in Kontact::IconSidePane::qt_metacall () from /usr/lib/libkontactprivate.so.4
#19 0x00007fd99a3dee0c in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#20 0x00007fd99b6de4af in Kontact::Navigator::pluginActivated () from /usr/lib/libkontactprivate.so.4
#21 0x00007fd99b6de540 in Kontact::Navigator::slotCurrentChanged () from /usr/lib/libkontactprivate.so.4
#22 0x00007fd99b6dec71 in Kontact::Navigator::qt_metacall () from /usr/lib/libkontactprivate.so.4
#23 0x00007fd99a3dee0c in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#24 0x00007fd999d9690a in QItemSelectionModel::currentChanged () from /usr/lib/libQtGui.so.4
#25 0x00007fd999d96a52 in QItemSelectionModel::setCurrentIndex () from /usr/lib/libQtGui.so.4
#26 0x00007fd999d4b844 in QAbstractItemView::mousePressEvent () from /usr/lib/libQtGui.so.4
#27 0x00007fd9998c47f6 in QWidget::event () from /usr/lib/libQtGui.so.4
#28 0x00007fd999c1da06 in QFrame::event () from /usr/lib/libQtGui.so.4
#29 0x00007fd999d5080b in QAbstractItemView::viewportEvent () from /usr/lib/libQtGui.so.4
#30 0x00007fd99a3c9027 in QCoreApplicationPrivate::sendThroughObjectEventFilters () from /usr/lib/libQtCore.so.4
#31 0x00007fd999875dfc in QApplicationPrivate::notify_helper () from /usr/lib/libQtGui.so.4
#32 0x00007fd99987cf41 in QApplication::notify () from /usr/lib/libQtGui.so.4
#33 0x00007fd99ad66ff6 in KApplication::notify () from /usr/lib/libkdeui.so.5
#34 0x00007fd99a3c9d0c in QCoreApplication::notifyInternal () from /usr/lib/libQtCore.so.4
#35 0x00007fd99987c810 in QApplicationPrivate::sendMouseEvent () from /usr/lib/libQtGui.so.4
#36 0x00007fd9998e2714 in ?? () from /usr/lib/libQtGui.so.4
#37 0x00007fd9998e1409 in QApplication::x11ProcessEvent () from /usr/lib/libQtGui.so.4
#38 0x00007fd9999095fc in ?? () from /usr/lib/libQtGui.so.4
#39 0x00007fd9931dbdbe in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#40 0x00007fd9931df568 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#41 0x00007fd9931df690 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#42 0x00007fd99a3f21d6 in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#43 0x00007fd999908dde in ?? () from /usr/lib/libQtGui.so.4
#44 0x00007fd99a3c8612 in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#45 0x00007fd99a3c89e4 in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#46 0x00007fd99a3cab99 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#47 0x0000000000403ef7 in _start ()

Reported using DrKonqi