Application that crashed: kontact
Version of the application: 4.3.2
KDE Version: 4.3.2 (KDE 4.3.2)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-20-generic-pae i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
Kontact crashes when i launch it clicking on its icon. It usually happens from the second time that i launch it, during the current session. When i try to launch it again it suddendly after, it goes well.
If it might help: i have Korganizer and Knotes in the system tray (autostart).

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#6  0xb779b1fc in QString (this=0xa1f8220) at /usr/include/qt4/QtCore/qstring.h:711
#7  Kontact::Plugin::identifier (this=0xa1f8220) at ../../kontactinterfaces/plugin.cpp:97
#8  0xb77b550e in Kontact::MainWindow::activatePluginModule (this=0x9f74ac8) at ../../../kontact/src/mainwindow.cpp:303
#9  0xb77b55c4 in Kontact::MainWindow::setActivePluginModule (this=0x9f74ac8, module=...) at ../../../kontact/src/mainwindow.cpp:281
#10 0x0804bd0f in KontactApp::newInstance (this=0xbfb938b4) at ../../../kontact/src/main.cpp:147
#11 0xb74bf380 in KUniqueApplicationAdaptor::newInstance (this=0x9ef6d68, asn_id=..., args=...) at ../../kdeui/kernel/kuniqueapplication.cpp:459
#12 0xb74bfa92 in KUniqueApplicationAdaptor::qt_metacall (this=0x9ef6d68, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0xbfb92edc) at ./kuniqueapplication_p.moc:75
#13 0xb58c77b4 in QDBusConnectionPrivate::deliverCall (this=0x9e74c90, object=0x9ef6d68, msg=..., metaTypes=..., slotIdx=4) at qdbusintegrator.cpp:891
#14 0xb58c89c5 in QDBusConnectionPrivate::activateCall (this=0x9e74c90, object=0x9ef6d68, flags=337, msg=...) at qdbusintegrator.cpp:803
#15 0xb58c9234 in QDBusConnectionPrivate::activateObject (this=0x9e74c90, node=..., msg=..., pathStartPos=16) at qdbusintegrator.cpp:1347
#16 0xb58c94da in QDBusActivateObjectEvent::placeMetaCall (this=0xc22a868) at qdbusintegrator.cpp:1464
#17 0xb661b5fe in QObject::event (this=0xbfb938b4, e=0xc22a868) at kernel/qobject.cpp:1111
#18 0xb660affb in QCoreApplication::event (this=0xbfb938b4, e=0xc22a868) at kernel/qcoreapplication.cpp:1434
#19 0xb6a6d9a6 in QApplication::event (this=0xbfb938b4, e=0xc22a868) at kernel/qapplication.cpp:2317
#20 0xb6a67f54 in QApplicationPrivate::notify_helper (this=0x9e8cad8, receiver=0xbfb938b4, e=0xc22a868) at kernel/qapplication.cpp:4056
#21 0xb6a6f67c in QApplication::notify (this=0xbfb938b4, receiver=0xbfb938b4, e=0xc22a868) at kernel/qapplication.cpp:3603
#22 0xb74b7bfa in KApplication::notify (this=0xbfb938b4, receiver=0xbfb938b4, event=0xc22a868) at ../../kdeui/kernel/kapplication.cpp:302
#23 0xb660b6cb in QCoreApplication::notifyInternal (this=0xbfb938b4, receiver=0xbfb938b4, event=0xc22a868) at kernel/qcoreapplication.cpp:610
#24 0xb660c2b2 in QCoreApplication::sendEvent (receiver=0x0, event_type=0, data=0x9e5c820) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#25 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x9e5c820) at kernel/qcoreapplication.cpp:1247
#26 0xb660c47d in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1140
#27 0xb66363ff in QCoreApplication::sendPostedEvents (s=0x9e8a390) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#28 postEventSourceDispatch (s=0x9e8a390) at kernel/qeventdispatcher_glib.cpp:210
#29 0xb4900e88 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#30 0xb4904730 in ?? () from /lib/libglib-2.0.so.0
#31 0xb4904863 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#32 0xb663602c in QEventDispatcherGlib::processEvents (this=0x9e5c9f8, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#33 0xb6b08be5 in QGuiEventDispatcherGlib::processEvents (this=0x9e5c9f8, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#34 0xb6609c79 in QEventLoop::processEvents (this=0xbfb93814, flags=) at kernel/qeventloop.cpp:149
#35 0xb660a0ca in QEventLoop::exec (this=0xbfb93814, flags=...) at kernel/qeventloop.cpp:201
#36 0xb660c53f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#37 0xb6a67dd7 in QApplication::exec () at kernel/qapplication.cpp:3525
#38 0x0804b4e6 in main (argc=1, argv=0xbfb93ad4) at ../../../kontact/src/main.cpp:218

Reported using DrKonqi