Application that crashed: kontact
Version of the application: 4.3.0 rc1
KDE Version: 4.2.95 (KDE 4.2.95 (KDE 4.3 RC1))
Qt Version: 4.5.1
Operating System: Linux 2.6.28-13-generic i686
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
If I end Kontact the process still is present, if I start Kontact then it crashes - another start lets Kontact show up

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#6  0xb77e102c in Kontact::Plugin::identifier (this=0x8d9f438) at /usr/include/qt4/QtCore/qstring.h:711
#7  0xb77faff9 in Kontact::MainWindow::activatePluginModule (this=0x8a45bb0) at /build/buildd/kdepim-4.2.95a/kontact/src/mainwindow.cpp:303
#8  0xb77fb0a4 in Kontact::MainWindow::setActivePluginModule (this=0x8a45bb0, module=@0xbfd6d0b4) at /build/buildd/kdepim-4.2.95a/kontact/src/mainwindow.cpp:281
#9  0x0804ac57 in KontactApp::newInstance (this=0xbfd6dc18) at /build/buildd/kdepim-4.2.95a/kontact/src/main.cpp:147
#10 0xb6c99a66 in KUniqueApplicationAdaptor::newInstance (this=0x8a47370, asn_id=@0xa0482d8, args=@0x8adb7c8) at /build/buildd/kde4libs-4.2.95/kdeui/kernel/kuniqueapplication.cpp:454
#11 0xb6c99b0e in KUniqueApplicationAdaptor::qt_metacall (this=0x8a47370, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0xbfd6d308)
    at /build/buildd/kde4libs-4.2.95/obj-i486-linux-gnu/kdeui/kuniqueapplication_p.moc:75
#12 0xb5cc7e2a in QDBusConnectionPrivate::deliverCall (this=0x8a35e58, object=0x8a47370, msg=@0x9970458, metaTypes=@0x8f67b8c, slotIdx=4) at qdbusintegrator.cpp:891
#13 0xb5cc9149 in QDBusConnectionPrivate::activateCall (this=0x8a35e58, object=0x8a47370, flags=337, msg=@0x9970458) at qdbusintegrator.cpp:803
#14 0xb5cc95b1 in QDBusConnectionPrivate::activateObject (this=0x8a35e58, node=@0x9970444, msg=@0x9970458, pathStartPos=16) at qdbusintegrator.cpp:1375
#15 0xb5cc9aaa in QDBusActivateObjectEvent::placeMetaCall (this=0x9970418) at qdbusintegrator.cpp:1469
#16 0xb5bc0150 in QObject::event (this=0xbfd6dc18, e=0x9970418) at kernel/qobject.cpp:1118
#17 0xb5baf14b in QCoreApplication::event (this=0xbfd6dc18, e=0x9970418) at kernel/qcoreapplication.cpp:1434
#18 0xb6073509 in QApplication::event (this=0xbfd6dc18, e=0x9970418) at kernel/qapplication.cpp:2318
#19 0xb606dbcc in QApplicationPrivate::notify_helper (this=0x8a4f0d0, receiver=0xbfd6dc18, e=0x9970418) at kernel/qapplication.cpp:4057
#20 0xb6075ede in QApplication::notify (this=0xbfd6dc18, receiver=0xbfd6dc18, e=0x9970418) at kernel/qapplication.cpp:3604
#21 0xb6c923dd in KApplication::notify (this=0xbfd6dc18, receiver=0xbfd6dc18, event=0x9970418) at /build/buildd/kde4libs-4.2.95/kdeui/kernel/kapplication.cpp:302
#22 0xb5baf7ab in QCoreApplication::notifyInternal (this=0xbfd6dc18, receiver=0xbfd6dc18, event=0x9970418) at kernel/qcoreapplication.cpp:610
#23 0xb5bb0405 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x8a1dc08) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#24 0xb5bb05fd in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1140
#25 0xb5bdb58f in postEventSourceDispatch (s=0x8a51488) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#26 0xb4c83b88 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#27 0xb4c870eb in ?? () from /usr/lib/libglib-2.0.so.0
#28 0xb4c87268 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#29 0xb5bdb1d8 in QEventDispatcherGlib::processEvents (this=0x8a4e478, flags={i = -1076438296}) at kernel/qeventdispatcher_glib.cpp:324
#30 0xb610f765 in QGuiEventDispatcherGlib::processEvents (this=0x8a4e478, flags={i = -1076438248}) at kernel/qguieventdispatcher_glib.cpp:202
#31 0xb5baddda in QEventLoop::processEvents (this=0xbfd6db90, flags={i = -1076438184}) at kernel/qeventloop.cpp:149
#32 0xb5bae21a in QEventLoop::exec (this=0xbfd6db90, flags={i = -1076438120}) at kernel/qeventloop.cpp:200
#33 0xb5bb06c9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#34 0xb606da47 in QApplication::exec () at kernel/qapplication.cpp:3526
#35 0x0804bfef in main (argc=1, argv=0xbfd6df14) at /build/buildd/kdepim-4.2.95a/kontact/src/main.cpp:218

Reported using DrKonqi