Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.2.90 (KDE 4.2.90 (KDE 4.3 Beta2))
Qt Version: 4.5.1
Operating System: Linux 2.6.30-9-generic i686
Distribution: Ubuntu karmic (development branch)

What I was doing when the application crashed:
Plasma crashed when notifications icon in system tray was clicked. There were no active notifications at this moment. I don't know exacly how to reproduce it, because it happened only once, but maybe someone observed it too.

 -- Backtrace:
Application: Plasma Workspace (kdeinit), signal: Segmentation fault
[Current thread is 0 (LWP 8868)]

Thread 2 (Thread 0xacee9b90 (LWP 8878)):
#0  0x009e0422 in __kernel_vsyscall ()
#1  0x00c0a0e5 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0x00ad455d in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0x0015ff97 in QWaitCondition::wait (this=0x9b02360, mutex=0x9b0235c, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  0x063287f2 in QHostInfoAgent::run (this=0x9b02350) at kernel/qhostinfo.cpp:260
#5  0x0015ef5e in QThreadPrivate::start (arg=0x9b02350) at thread/qthread_unix.cpp:189
#6  0x00c064ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0x00ac570e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb8030930 (LWP 8868)):
[KCrash Handler]
#6  0x014903e6 in Plasma::ExtenderItem::config (this=0x9defe08) at ../../plasma/extenderitem.cpp:153
#7  0x0149207d in Plasma::ExtenderItem::isGroup (this=0x9defe08) at ../../plasma/extenderitem.cpp:328
#8  0x0148882f in Plasma::Extender::isEmpty (this=0x990df68) at ../../plasma/extender.cpp:656
#9  0x014a0cd0 in Plasma::PopupAppletPrivate::internalTogglePopup (this=0x98018a0) at ../../plasma/popupapplet.cpp:522
#10 0x014a1193 in Plasma::PopupApplet::qt_metacall (this=0x97c0c60, _c=QMetaObject::InvokeMetaMethod, _id=38, _a=0xbfd2ddec) at ./popupapplet.moc:83
#11 0x0653496a in ?? () from /usr/lib/kde4/plasma_applet_systemtray.so
#12 0x00264ff3 in QMetaObject::activate (sender=0x99b8898, from_signal_index=5, to_signal_index=5, argv=0x0) at kernel/qobject.cpp:3120
#13 0x00265c42 in QMetaObject::activate (sender=0x99b8898, m=0x15d22ec, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3194
#14 0x0150c8a7 in Plasma::BusyWidget::clicked (this=0x99b8898) at ./busywidget.moc:118
#15 0x0150c8dd in Plasma::BusyWidget::mousePressEvent (this=0x99b8898, event=0xbfd2e554) at ../../plasma/widgets/busywidget.cpp:207
#16 0x053f5fe2 in QGraphicsItem::sceneEvent (this=0x99b88a0, event=0xbfd2e554) at graphicsview/qgraphicsitem.cpp:5013
#17 0x05442e4f in QGraphicsWidget::sceneEvent (this=0x99b8898, event=0xbfd2e554) at graphicsview/qgraphicswidget.cpp:1110
#18 0x05418044 in QGraphicsScenePrivate::sendEvent (this=0x9596438, item=0x99b88a0, event=0xbfd2e554) at graphicsview/qgraphicsscene.cpp:1159
#19 0x05419673 in QGraphicsScenePrivate::sendMouseEvent (this=0x9596438, mouseEvent=0xbfd2e554) at graphicsview/qgraphicsscene.cpp:1230
#20 0x05425736 in QGraphicsScenePrivate::mousePressEventHandler (this=0x9596438, mouseEvent=0xbfd2e554) at graphicsview/qgraphicsscene.cpp:1319
#21 0x05426387 in QGraphicsScene::event (this=0x95cf9b0, event=0xbfd2e554) at graphicsview/qgraphicsscene.cpp:3810
#22 0x04dbeaa4 in QApplicationPrivate::notify_helper (this=0x94e9200, receiver=0x95cf9b0, e=0xbfd2e554) at kernel/qapplication.cpp:4057
#23 0x04dc61dc in QApplication::notify (this=0x94d64e0, receiver=0x95cf9b0, e=0xbfd2e554) at kernel/qapplication.cpp:3604
#24 0x0114602a in KApplication::notify (this=0x94d64e0, receiver=0x95cf9b0, event=0xbfd2e554) at ../../kdeui/kernel/kapplication.cpp:302
#25 0x0024f17b in QCoreApplication::notifyInternal (this=0x94d64e0, receiver=0x95cf9b0, event=0xbfd2e554) at kernel/qcoreapplication.cpp:610
#26 0x05434249 in QGraphicsView::mousePressEvent (this=0x99265d8, event=0xbfd2eb70) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#27 0x04e13c76 in QWidget::event (this=0x99265d8, event=0xbfd2eb70) at kernel/qwidget.cpp:7517
#28 0x051f2353 in QFrame::event (this=0x99265d8, e=0xbfd2eb70) at widgets/qframe.cpp:559
#29 0x05290fb4 in QAbstractScrollArea::viewportEvent (this=0x158f382, e=0x19) at widgets/qabstractscrollarea.cpp:962
#30 0x05437f4f in QGraphicsView::viewportEvent (this=0x99265d8, event=0xbfd2eb70) at graphicsview/qgraphicsview.cpp:2897
#31 0x052935b5 in QAbstractScrollAreaFilter::eventFilter (this=0x9b4aa98, o=0x9aa0a80, e=0xbfd2eb70) at widgets/qabstractscrollarea_p.h:100
#32 0x0024e2ea in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=0x94e9200, receiver=0x9aa0a80, event=0xbfd2eb70) at kernel/qcoreapplication.cpp:726
#33 0x04dbea7c in QApplicationPrivate::notify_helper (this=0x94e9200, receiver=0x9aa0a80, e=0xbfd2eb70) at kernel/qapplication.cpp:4053
#34 0x04dc6b93 in QApplication::notify (this=0x94d64e0, receiver=0x9aa0a80, e=0xbfd2eb70) at kernel/qapplication.cpp:3759
#35 0x0114602a in KApplication::notify (this=0x94d64e0, receiver=0x9aa0a80, event=0xbfd2eb70) at ../../kdeui/kernel/kapplication.cpp:302
#36 0x0024f17b in QCoreApplication::notifyInternal (this=0x94d64e0, receiver=0x9aa0a80, event=0xbfd2eb70) at kernel/qcoreapplication.cpp:610
#37 0x04dc5ace in QApplicationPrivate::sendMouseEvent (receiver=0x9aa0a80, event=0xbfd2eb70, alienWidget=0x9aa0a80, nativeWidget=0x99265d8, buttonDown=0x5664aa0, lastMouseReceiver=@0x5664aa4)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#38 0x04e342b0 in QETWidget::translateMouseEvent (this=0x99265d8, event=0xbfd301bc) at kernel/qapplication_x11.cpp:4448
#39 0x04e33743 in QApplication::x11ProcessEvent (this=0x94d64e0, event=0xbfd301bc) at kernel/qapplication_x11.cpp:3444
#40 0x04e5fee2 in x11EventSourceDispatch (s=0x94eb998, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#41 0x00914b18 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#42 0x009180b0 in ?? () from /usr/lib/libglib-2.0.so.0
#43 0x009181e3 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#44 0x00279d0c in QEventDispatcherGlib::processEvents (this=0x94e7b40, flags={i = 36}) at kernel/qeventdispatcher_glib.cpp:324
#45 0x04e5f5c5 in QGuiEventDispatcherGlib::processEvents (this=0x94e7b40, flags={i = 36}) at kernel/qguieventdispatcher_glib.cpp:202
#46 0x0024d729 in QEventLoop::processEvents (this=0xbfd304b4, flags=) at kernel/qeventloop.cpp:149
#47 0x0024db72 in QEventLoop::exec (this=0xbfd304b4, flags={i = 0}) at kernel/qeventloop.cpp:200
#48 0x0024fecf in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#49 0x04dbe927 in QApplication::exec () at kernel/qapplication.cpp:3526
#50 0x05a2bedd in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#51 0x0804dd32 in launch (argc=<value optimized out>, _name=<value optimized out>, args=<value optimized out>, cwd=0x0, envc=0, envs=0x94adce0 "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x8051128 "0") at ../../kinit/kinit.cpp:671
#52 0x0804e935 in handle_launcher_request (sock=<value optimized out>, who=<value optimized out>) at ../../kinit/kinit.cpp:1163
#53 0x0804eec3 in handle_requests (waitForPid=<value optimized out>) at ../../kinit/kinit.cpp:1356
#54 0x0804fb0f in main (argc=2, argv=0xbfd30d04, envp=0xbfd30d10) at ../../kinit/kinit.cpp:1783

Reported using DrKonqi