Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.2 (KDE 4.3.2)
Qt Version: 4.5.3
Operating System: Linux 2.6.31-ARCH i686

What I was doing when the application crashed:
I was playing urban terror, and suddenly I was dumped back at the login screen, with low resolution. I come back in, and this pops up.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0xb57b3700 (LWP 8984))]

Thread 2 (Thread 0xa874bb70 (LWP 8985)):
#0  0xb78bd424 in __kernel_vsyscall ()
#1  0xb765db95 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb76b7937 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib/libQtCore.so.4
#3  0xb5f39562 in ?? () from /usr/lib/libQtNetwork.so.4
#4  0xb76b6922 in ?? () from /usr/lib/libQtCore.so.4
#5  0xb765965c in start_thread () from /lib/libpthread.so.0
#6  0xb61b63be in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb57b3700 (LWP 8984)):
[KCrash Handler]
#6  0xa8ce79dc in AbstractTaskItem::basicPreferredSize() const () from /usr/lib/kde4/plasma_applet_tasks.so
#7  0xa8ce3559 in TaskItemLayout::maximumRows() () from /usr/lib/kde4/plasma_applet_tasks.so
#8  0xa8cecdb4 in TaskGroupItem::optimumCapacity() () from /usr/lib/kde4/plasma_applet_tasks.so
#9  0xa8cde488 in Tasks::adjustGroupingStrategy() () from /usr/lib/kde4/plasma_applet_tasks.so
#10 0xa8cde71c in Tasks::constraintsEvent(QFlags<Plasma::Constraint>) () from /usr/lib/kde4/plasma_applet_tasks.so
#11 0xb54c2d93 in Plasma::Applet::flushPendingConstraintsEvents() () from /usr/lib/libplasma.so.3
#12 0xb54c34c8 in Plasma::Applet::timerEvent(QTimerEvent*) () from /usr/lib/libplasma.so.3
#13 0xb77b4a5f in QObject::event(QEvent*) () from /usr/lib/libQtCore.so.4
#14 0xb6a80554 in QGraphicsWidget::event(QEvent*) () from /usr/lib/libQtGui.so.4
#15 0xb64333a4 in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#16 0xb643aa8c in QApplication::notify(QObject*, QEvent*) () from /usr/lib/libQtGui.so.4
#17 0xb6e760aa in KApplication::notify(QObject*, QEvent*) () from /usr/lib/libkdeui.so.5
#18 0xb77a4e8b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/libQtCore.so.4
#19 0xb77d27ce in ?? () from /usr/lib/libQtCore.so.4
#20 0xb77cf8d7 in ?? () from /usr/lib/libQtCore.so.4
#21 0xb604b328 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#22 0xb604eba0 in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#23 0xb604ecd3 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#24 0xb77cf5f5 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#25 0xb64d1185 in ?? () from /usr/lib/libQtGui.so.4
#26 0xb77a3479 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#27 0xb77a38ca in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/libQtCore.so.4
#28 0xb77a5d3f in QCoreApplication::exec() () from /usr/lib/libQtCore.so.4
#29 0xb6433227 in QApplication::exec() () from /usr/lib/libQtGui.so.4
#30 0xb42c960d in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#31 0x0804de22 in _start ()

Reported using DrKonqi