Application that crashed: kontact
Version of the application: 4.3.1
KDE Version: 4.3.1 (KDE 4.3.1)
Qt Version: 4.5.2
Operating System: Linux 2.6.28-11-generic i686
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
just closed kontact, wait some seconds and restarted it ==> crash

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#6  0xb789f02c in Kontact::Plugin::identifier (this=0x9c4df08) at /usr/include/qt4/QtCore/qstring.h:711
#7  0xb78b8ff9 in Kontact::MainWindow::activatePluginModule (this=0x9860228) at /build/buildd/kdepim-4.3.1/kontact/src/mainwindow.cpp:303
#8  0xb78b90a4 in Kontact::MainWindow::setActivePluginModule (this=0x9860228, module=@0xbff302a4) at /build/buildd/kdepim-4.3.1/kontact/src/mainwindow.cpp:281
#9  0x0804ac57 in KontactApp::newInstance (this=0xbff30e08) at /build/buildd/kdepim-4.3.1/kontact/src/main.cpp:147
#10 0xb6d54ec6 in KUniqueApplicationAdaptor::newInstance (this=0x98e6638, asn_id=@0x9c56b60, args=@0x9d0c3c8) at /build/buildd/kde4libs-4.3.1/kdeui/kernel/kuniqueapplication.cpp:459
#11 0xb6d54f6e in KUniqueApplicationAdaptor::qt_metacall (this=0x98e6638, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0xbff304f8)
    at /build/buildd/kde4libs-4.3.1/obj-i486-linux-gnu/kdeui/kuniqueapplication_p.moc:75
#12 0xb5da8e5a in QDBusConnectionPrivate::deliverCall (this=0x9851f40, object=0x98e6638, msg=@0xc387ec8, metaTypes=@0xdf8db8c, slotIdx=4) at qdbusintegrator.cpp:891
#13 0xb5daa179 in QDBusConnectionPrivate::activateCall (this=0x9851f40, object=0x98e6638, flags=337, msg=@0xc387ec8) at qdbusintegrator.cpp:803
#14 0xb5daa5e1 in QDBusConnectionPrivate::activateObject (this=0x9851f40, node=@0xc387eb4, msg=@0xc387ec8, pathStartPos=16) at qdbusintegrator.cpp:1370
#15 0xb5daaada in QDBusActivateObjectEvent::placeMetaCall (this=0xc387e88) at qdbusintegrator.cpp:1464
#16 0xb5ca13b0 in QObject::event (this=0xbff30e08, e=0xc387e88) at kernel/qobject.cpp:1111
#17 0xb5c9056b in QCoreApplication::event (this=0xbff30e08, e=0xc387e88) at kernel/qcoreapplication.cpp:1434
#18 0xb6159679 in QApplication::event (this=0xbff30e08, e=0xc387e88) at kernel/qapplication.cpp:2317
#19 0xb6153d3c in QApplicationPrivate::notify_helper (this=0x986f1b0, receiver=0xbff30e08, e=0xc387e88) at kernel/qapplication.cpp:4056
#20 0xb615c03e in QApplication::notify (this=0xbff30e08, receiver=0xbff30e08, e=0xc387e88) at kernel/qapplication.cpp:3603
#21 0xb6d4d85d in KApplication::notify (this=0xbff30e08, receiver=0xbff30e08, event=0xc387e88) at /build/buildd/kde4libs-4.3.1/kdeui/kernel/kapplication.cpp:302
#22 0xb5c90bcb in QCoreApplication::notifyInternal (this=0xbff30e08, receiver=0xbff30e08, event=0xc387e88) at kernel/qcoreapplication.cpp:610
#23 0xb5c91825 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x983a440) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#24 0xb5c91a1d in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1140
#25 0xb5cbc6af in postEventSourceDispatch (s=0x9867918) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#26 0xb4d61b88 in IA__g_main_context_dispatch (context=0x9867898) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:1814
#27 0xb4d650eb in g_main_context_iterate (context=0x9867898, block=1, dispatch=1, self=0x9872f88) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:2448
#28 0xb4d65268 in IA__g_main_context_iteration (context=0x9867898, may_block=1) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:2511
#29 0xb5cbc2f8 in QEventDispatcherGlib::processEvents (this=0x983a028, flags={i = -1074590504}) at kernel/qeventdispatcher_glib.cpp:327
#30 0xb61f5a75 in QGuiEventDispatcherGlib::processEvents (this=0x983a028, flags={i = -1074590456}) at kernel/qguieventdispatcher_glib.cpp:202
#31 0xb5c8f1fa in QEventLoop::processEvents (this=0xbff30d80, flags={i = -1074590392}) at kernel/qeventloop.cpp:149
#32 0xb5c8f642 in QEventLoop::exec (this=0xbff30d80, flags={i = -1074590328}) at kernel/qeventloop.cpp:201
#33 0xb5c91ae9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#34 0xb6153bb7 in QApplication::exec () at kernel/qapplication.cpp:3525
#35 0x0804bfef in main (argc=1, argv=0xbff31104) at /build/buildd/kdepim-4.3.1/kontact/src/main.cpp:218

Reported using DrKonqi