Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.2.93 (KDE 4.2.93 (KDE 4.3 >= 20090623)) "release 1"
Qt Version: 4.5.2
Operating System: Linux 2.6.27.23-0.1-default x86_64
Distribution: "openSUSE 11.1 (x86_64)"

What I was doing when the application crashed:
After updating to the latest svn version available from openSUSE KDE4 community repos (4.2.93svn985654-1.1), plasma-desktop crashes an awful lot, but mostly when switching desktops while desktop effects are enabled (having desktop effects enabled is not a requisite, however, as I can reproduce it with them disabled).

 -- Backtrace:
Application: Plasma Workspace (plasma-desktop), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f511b79c790 (LWP 6956))]

Thread 2 (Thread 0x7f5108632950 (LWP 6964)):
#0  0x00007f5122dd7d59 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007f5123048e19 in QWaitCondition::wait(QMutex*, unsigned long) () from /usr/lib64/libQtCore.so.4
#2  0x00007f51267c387c in ?? () from /usr/lib64/libQtNetwork.so.4
#3  0x00007f5123047e65 in ?? () from /usr/lib64/libQtCore.so.4
#4  0x00007f5122dd4070 in start_thread () from /lib64/libpthread.so.0
#5  0x00007f51223cd10d in clone () from /lib64/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f511b79c790 (LWP 6956)):
[KCrash Handler]
#5  0x0000000000b17030 in ?? ()
#6  0x00007f510a262acc in TaskItemLayout::size (this=<value optimized out>) at /usr/src/debug/kdebase-workspace-4.2.93svn985654/plasma/applets/tasks/taskitemlayout.cpp:152
#7  0x00007f510a262e12 in TaskItemLayout::gridLayoutSize (this=0x13a3890) at /usr/src/debug/kdebase-workspace-4.2.93svn985654/plasma/applets/tasks/taskitemlayout.cpp:220
#8  0x00007f510a262eab in TaskItemLayout::layoutItems (this=0x13a3890) at /usr/src/debug/kdebase-workspace-4.2.93svn985654/plasma/applets/tasks/taskitemlayout.cpp:245
#9  0x00007f510a26ad4a in TaskGroupItem::constraintsChanged (this=0xd78dd0, constraints={i = 804359344}) at /usr/src/debug/kdebase-workspace-4.2.93svn985654/plasma/applets/tasks/taskgroupitem.cpp:694
#10 0x00007f510a26f79b in TaskGroupItem::qt_metacall (this=0xd78dd0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff2ff18dc0)
    at /usr/src/debug/kdebase-workspace-4.2.93svn985654/build/plasma/applets/tasks/taskgroupitem.moc:108
#11 0x00007f51231466e2 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/lib64/libQtCore.so.4
#12 0x00007f510a25dd02 in Tasks::constraintsChanged (this=0x13a3890, _t1=<value optimized out>) at /usr/src/debug/kdebase-workspace-4.2.93svn985654/build/plasma/applets/tasks/tasks.moc:98
#13 0x00007f510a25e13f in Tasks::constraintsEvent (this=0xafbb20, constraints={i = 804359904}) at /usr/src/debug/kdebase-workspace-4.2.93svn985654/plasma/applets/tasks/tasks.cpp:169
#14 0x00007f51274e2e09 in Plasma::Applet::flushPendingConstraintsEvents() () from /usr/lib64/libplasma.so.3
#15 0x00007f51274e3585 in Plasma::Applet::timerEvent(QTimerEvent*) () from /usr/lib64/libplasma.so.3
#16 0x00007f5123141533 in QObject::event(QEvent*) () from /usr/lib64/libQtCore.so.4
#17 0x00007f5123e0a71b in QGraphicsWidget::event(QEvent*) () from /usr/lib64/libQtGui.so.4
#18 0x00007f5123835b0d in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib64/libQtGui.so.4
#19 0x00007f512383dd9a in QApplication::notify(QObject*, QEvent*) () from /usr/lib64/libQtGui.so.4
#20 0x00007f51261005cb in KApplication::notify(QObject*, QEvent*) () from /usr/lib64/libkdeui.so.5
#21 0x00007f512313194c in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib64/libQtCore.so.4
#22 0x00007f512315eb60 in ?? () from /usr/lib64/libQtCore.so.4
#23 0x00007f512315addd in ?? () from /usr/lib64/libQtCore.so.4
#24 0x00007f511f14c0fb in g_main_context_dispatch () from /usr/lib64/libglib-2.0.so.0
#25 0x00007f511f14f8cd in ?? () from /usr/lib64/libglib-2.0.so.0
#26 0x00007f511f14fa8b in g_main_context_iteration () from /usr/lib64/libglib-2.0.so.0
#27 0x00007f512315ad3f in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#28 0x00007f51238ccfef in ?? () from /usr/lib64/libQtGui.so.4
#29 0x00007f51231301d2 in QEventLoop::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#30 0x00007f51231305a4 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib64/libQtCore.so.4
#31 0x00007f5123132894 in QCoreApplication::exec() () from /usr/lib64/libQtCore.so.4
#32 0x00007f5127ab3a6b in kdemain (argc=1, argv=0x7fff2ff19d78) at /usr/src/debug/kdebase-workspace-4.2.93svn985654/plasma/shells/desktop/main.cpp:50
#33 0x00007f5122318586 in __libc_start_main () from /lib64/libc.so.6
#34 0x0000000000400819 in _start () at ../sysdeps/x86_64/elf/start.S:113

Reported using DrKonqi