Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.2 (KDE 4.3.2)
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:
Immediate crash upon addition of task manager to tray

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0xb77eb700 (LWP 1623))]

Thread 2 (Thread 0xac730b70 (LWP 1624)):
#0  0x00395422 in __kernel_vsyscall ()
#1  0x00371e15 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0x00aac78d in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0x0015fe67 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQtCore.so.4
#4  0x00c48922 in ?? () from /usr/lib/libQtNetwork.so.4
#5  0x0015ee32 in ?? () from /usr/lib/libQtCore.so.4
#6  0x0036d80e in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0x00a9f7ee in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb77eb700 (LWP 1623)):
[KCrash Handler]
#6  0x0257818a in QGraphicsItem::isWidget() const () from /usr/lib/libQtGui.so.4
#7  0x025b1527 in QGraphicsScene::event(QEvent*) () from /usr/lib/libQtGui.so.4
#8  0x01f74f54 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#9  0x01f7c67c in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#10 0x011c5bfa in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#11 0x0024f6cb in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#12 0x025c25e7 in QGraphicsView::viewportEvent(QEvent*) () from /usr/lib/libQtGui.so.4
#13 0x0241aa95 in ?? () from /usr/lib/libQtGui.so.4
#14 0x0024e83a in QCoreApplicationPrivate::sendThroughObjectEventFilters(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#15 0x01f74f2c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#16 0x01f7c5ca in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#17 0x011c5bfa in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#18 0x0024f6cb in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#19 0x01fc9ad5 in QWidget::event(QEvent*) () from /usr/lib/libQtGui.so.4
#20 0x02379633 in QFrame::event(QEvent*) () from /usr/lib/libQtGui.so.4
#21 0x02418faa in QAbstractScrollArea::event(QEvent*) () from /usr/lib/libQtGui.so.4
#22 0x025c2406 in QGraphicsView::event(QEvent*) () from /usr/lib/libQtGui.so.4
#23 0x01f74f54 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#24 0x01f7c5ca in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#25 0x011c5bfa in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#26 0x0024f6cb in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#27 0x01f7fdf6 in QApplication::setActiveWindow(QWidget*) () from /usr/lib/libQtGui.so.4
#28 0x01fe921f in QApplication::x11ProcessEvent(_XEvent*) () from /usr/lib/libQtGui.so.4
#29 0x02016502 in ?? () from /usr/lib/libQtGui.so.4
#30 0x00b4fe88 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#31 0x00b53730 in ?? () from /lib/libglib-2.0.so.0
#32 0x00b53863 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#33 0x0027a02c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#34 0x02015be5 in ?? () from /usr/lib/libQtGui.so.4
#35 0x0024dc79 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#36 0x0024e0ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#37 0x0025053f in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#38 0x01f74dd7 in QApplication::exec() () from /usr/lib/libQtGui.so.4
#39 0x0409280d in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#40 0x0804dde1 in _start ()

Reported using DrKonqi