Application that crashed: kontact
Version of the application: 4.3.4
KDE Version: 4.3.4 (KDE 4.3.4)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-16-generic i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
After system startup kontact started in two instances. After closing one - everything was fine. When I klicked on Email Kontact crashed immediately.  

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#6  QListData::begin (this=0x8d18ec8) at /usr/include/qt4/QtCore/qlist.h:90
#7  QList<KMFilter*>::begin (this=0x8d18ec8) at /usr/include/qt4/QtCore/qlist.h:238
#8  KMMainWidget::initializeFilterActions (this=0x8d18ec8) at ../../kmail/kmmainwidget.cpp:4783
#9  0x0291e356 in KMailPart::guiActivateEvent (this=0x8be2230, e=0xbfd37b5c) at ../../kmail/kmail_part.cpp:183
#10 0x005cbbe4 in KParts::Part::customEvent (this=0x8be2230, ev=0xbfd37b5c) at ../../kparts/part.cpp:320
#11 0x004d165f in QObject::event (this=0x8be2230, e=0xbfd37b5c) at kernel/qobject.cpp:1142
#12 0x01009f54 in QApplicationPrivate::notify_helper (this=0x888bee0, receiver=0x8be2230, e=0xbfd37b5c) at kernel/qapplication.cpp:4056
#13 0x0101167c in QApplication::notify (this=0xbfd3a3b4, receiver=0x8be2230, e=0xbfd37b5c) at kernel/qapplication.cpp:3603
#14 0x00a9d1aa in KApplication::notify (this=0xbfd3a3b4, receiver=0x8be2230, event=0xbfd37b5c) at ../../kdeui/kernel/kapplication.cpp:302
#15 0x004c16cb in QCoreApplication::notifyInternal (this=0xbfd3a3b4, receiver=0x8be2230, event=0xbfd37b5c) at kernel/qcoreapplication.cpp:610
#16 0x005d78be in QCoreApplication::sendEvent (this=0x89102f8, part=0x8be2230) at /usr/include/qt4/QtCore/qcoreapplication.h:213
#17 KParts::MainWindow::createGUI (this=0x89102f8, part=0x8be2230) at ../../kparts/mainwindow.cpp:127
#18 0x00ed5047 in Kontact::MainWindow::selectPlugin (this=0x89102f8, plugin=0x8be3a20) at ../../../kontact/src/mainwindow.cpp:824
#19 0x00ed9ba2 in Kontact::MainWindow::qt_metacall (this=0x89102f8, _c=QMetaObject::InvokeMetaMethod, _id=53, _a=0xbfd37e28) at ./mainwindow.moc:107
#20 0x004d7263 in QMetaObject::activate (sender=0x890ee08, from_signal_index=27, to_signal_index=27, argv=0xbfd37e28) at kernel/qobject.cpp:3113
#21 0x004d7ec2 in QMetaObject::activate (sender=0x890ee08, m=0xee75e4, local_signal_index=0, argv=0xbfd37e28) at kernel/qobject.cpp:3187
#22 0x00edaf33 in Kontact::SidePaneBase::pluginSelected (this=0x890ee08, _t1=0x8be3a20) at ./sidepanebase.moc:84
#23 0x00edaf9d in Kontact::SidePaneBase::qt_metacall (this=0x890ee08, _c=QMetaObject::InvokeMetaMethod, _id=27, _a=0xbfd37f88) at ./sidepanebase.moc:71
#24 0x00edb25a in Kontact::IconSidePane::qt_metacall (this=0x890ee08, _c=QMetaObject::InvokeMetaMethod, _id=27, _a=0xbfd37f88) at ./iconsidepane.moc:133
#25 0x004d7263 in QMetaObject::activate (sender=0x8948ed0, from_signal_index=70, to_signal_index=70, argv=0xbfd37f88) at kernel/qobject.cpp:3113
#26 0x004d7ec2 in QMetaObject::activate (sender=0x8948ed0, m=0xee7710, local_signal_index=0, argv=0xbfd37f88) at kernel/qobject.cpp:3187
#27 0x00edb333 in Kontact::Navigator::pluginActivated (this=0x8948ed0, _t1=0x8be3a20) at ./iconsidepane.moc:90
#28 0x00edb3be in Kontact::Navigator::slotCurrentChanged (this=0x8948ed0, current=...) at ../../../kontact/src/iconsidepane.cpp:436
#29 0x00edbccd in Kontact::Navigator::qt_metacall (this=0x8948ed0, _c=QMetaObject::InvokeMetaMethod, _id=71, _a=0xbfd380e4) at ./iconsidepane.moc:76
#30 0x004d7263 in QMetaObject::activate (sender=0x88fc380, from_signal_index=5, to_signal_index=5, argv=0xbfd380e4) at kernel/qobject.cpp:3113
#31 0x004d7ec2 in QMetaObject::activate (sender=0x88fc380, m=0x1878290, local_signal_index=1, argv=0xbfd380e4) at kernel/qobject.cpp:3187
#32 0x015ac069 in QItemSelectionModel::currentChanged (this=0x88fc380, _t1=..., _t2=...) at .moc/release-shared/moc_qitemselectionmodel.cpp:153
#33 0x015ac202 in QItemSelectionModel::setCurrentIndex (this=0x88fc380, index=..., command=...) at itemviews/qitemselectionmodel.cpp:1123
#34 0x0155c504 in QAbstractItemView::mousePressEvent (this=0x8948ed0, event=0xbfd389d0) at itemviews/qabstractitemview.cpp:1514
#35 0x0105eff6 in QWidget::event (this=0x8948ed0, event=0xbfd389d0) at kernel/qwidget.cpp:7545
#36 0x0140e633 in QFrame::event (this=0x8948ed0, e=0xbfd389d0) at widgets/qframe.cpp:559
#37 0x014ad494 in QAbstractScrollArea::viewportEvent (this=0x7ffeff4, e=0x0) at widgets/qabstractscrollarea.cpp:962
#38 0x01561087 in QAbstractItemView::viewportEvent (this=0x8948ed0, event=0xbfd389d0) at itemviews/qabstractitemview.cpp:1476
#39 0x014afa95 in QAbstractScrollAreaPrivate::viewportEvent (this=0x892bee8, o=0x891e0b0, e=0xbfd389d0) at widgets/qabstractscrollarea_p.h:100
#40 QAbstractScrollAreaFilter::eventFilter (this=0x892bee8, o=0x891e0b0, e=0xbfd389d0) at widgets/qabstractscrollarea_p.h:111
#41 0x004c083a in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=0x888bee0, receiver=0x891e0b0, event=0xbfd389d0) at kernel/qcoreapplication.cpp:726
#42 0x01009f2c in QApplicationPrivate::notify_helper (this=0x888bee0, receiver=0x891e0b0, e=0xbfd389d0) at kernel/qapplication.cpp:4052
#43 0x01012033 in QApplication::notify (this=0xbfd3a3b4, receiver=0x891e0b0, e=0xbfd389d0) at kernel/qapplication.cpp:3758
#44 0x00a9d1aa in KApplication::notify (this=0xbfd3a3b4, receiver=0x891e0b0, event=0xbfd389d0) at ../../kdeui/kernel/kapplication.cpp:302
#45 0x004c16cb in QCoreApplication::notifyInternal (this=0xbfd3a3b4, receiver=0x891e0b0, event=0xbfd389d0) at kernel/qcoreapplication.cpp:610
#46 0x01010f6e in QCoreApplication::sendSpontaneousEvent (receiver=0x891e0b0, event=0xbfd389d0, alienWidget=0x891e0b0, nativeWidget=0x89102f8, buttonDown=0x1884aa0, lastMouseReceiver=...)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#47 QApplicationPrivate::sendMouseEvent (receiver=0x891e0b0, event=0xbfd389d0, alienWidget=0x891e0b0, nativeWidget=0x89102f8, buttonDown=0x1884aa0, lastMouseReceiver=...)
    at kernel/qapplication.cpp:2924
#48 0x0107f7c0 in QETWidget::translateMouseEvent (this=0x89102f8, event=0xbfd3a01c) at kernel/qapplication_x11.cpp:4409
#49 0x0107ec4b in QApplication::x11ProcessEvent (this=0xbfd3a3b4, event=0xbfd3a01c) at kernel/qapplication_x11.cpp:3428
#50 0x010ab502 in x11EventSourceDispatch (s=0x88893a8, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#51 0x041d1e88 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#52 0x041d5730 in ?? () from /lib/libglib-2.0.so.0
#53 0x041d5863 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#54 0x004ec02c in QEventDispatcherGlib::processEvents (this=0x885a9f8, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#55 0x010aabe5 in QGuiEventDispatcherGlib::processEvents (this=0x885a9f8, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#56 0x004bfc79 in QEventLoop::processEvents (this=0xbfd3a314, flags=) at kernel/qeventloop.cpp:149
#57 0x004c00ca in QEventLoop::exec (this=0xbfd3a314, flags=...) at kernel/qeventloop.cpp:201
#58 0x004c253f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#59 0x01009dd7 in QApplication::exec () at kernel/qapplication.cpp:3525
#60 0x0804b4e6 in main (argc=3, argv=0xbfd3a5d4) at ../../../kontact/src/main.cpp:218

Reported using DrKonqi