Version:           svn r945049 (using Devel)
OS:                Linux
Installed from:    Compiled sources

Sorry for the "non-descriptiveness" of the short description.

I was hovering the cursor over my contact list in Kopete to see more details about each contact and OpenOffice was loading in the background. Then plasma-desktop crashed unexpectedly.

Backtrace from the core dump:

#0  0xb7f87424 in __kernel_vsyscall ()
#1  0xb6533fc0 in raise () from /lib/libpthread.so.0
#2  0xb775277b in KCrash::defaultCrashHandler (sig=-1236029452)
    at /home/kubo/kde4/build/kdelibs/kdeui/util/kcrash.cpp:258
#3  <signal handler called>
#4  0xa818a0e2 in TaskManager::AbstractGroupingStrategy::closeGroup (this=0x8c3e8d8,
    group=0x8f62590)
    at /home/kubo/kde4/build/kdebase/workspace/libs/taskmanager/abstractgroupingstrategy.cpp:142
#5  0xa81941b4 in TaskManager::ProgramGroupingStrategy::checkGroup (this=0x8c3e8d8)
    at /home/kubo/kde4/build/kdebase/workspace/libs/taskmanager/strategies/programgroupingstrategy.cpp:196
#6  0xa8194b0b in TaskManager::ProgramGroupingStrategy::qt_metacall (this=0x8c3e8d8,
    _c=QMetaObject::InvokeMetaMethod, _id=0, _a=0xbfba3b4c)
    at /home/kubo/kde4/build/build/kdebase/workspace/libs/taskmanager/programgroupingstrategy.moc:68
#7  0xb66a45a7 in QMetaObject::activate (sender=0x8f62590, from_signal_index=22,
    to_signal_index=22, argv=0xbfba3b4c)
    at /home/kubo/kde4/build/qt-copy/src/corelib/kernel/qobject.cpp:3066
#8  0xb66a5973 in QMetaObject::activate (sender=0x8f62590, m=0xa81b7194, local_signal_index=1,
    argv=0xbfba3b4c) at /home/kubo/kde4/build/qt-copy/src/corelib/kernel/qobject.cpp:3143
#9  0xa81a5fc3 in TaskManager::TaskGroup::itemRemoved (this=0x8f62590, _t1=0x8b0fc40)
    at /home/kubo/kde4/build/build/kdebase/workspace/libs/taskmanager/taskgroup.moc:143
#10 0xa81a7736 in TaskManager::TaskGroup::remove (this=0x8f62590, item=0x8b0fc40)
    at /home/kubo/kde4/build/kdebase/workspace/libs/taskmanager/taskgroup.cpp:171
#11 0xa818d963 in TaskManager::GroupManagerPrivate::removeTask (this=0x899cc00, task=
      {d = 0xbfba3bec})
    at /home/kubo/kde4/build/kdebase/workspace/libs/taskmanager/groupmanager.cpp:289
#12 0xa818ee74 in TaskManager::GroupManager::qt_metacall (this=0x8984b00,
    _c=QMetaObject::InvokeMetaMethod, _id=10, _a=0xbfba3cec)
    at /home/kubo/kde4/build/build/kdebase/workspace/libs/taskmanager/groupmanager.moc:99
#13 0xb66a45a7 in QMetaObject::activate (sender=0x895ffa0, from_signal_index=5,
    to_signal_index=5, argv=0xbfba3cec)
    at /home/kubo/kde4/build/qt-copy/src/corelib/kernel/qobject.cpp:3066
#14 0xb66a5973 in QMetaObject::activate (sender=0x895ffa0, m=0xa81b735c, local_signal_index=1,
    argv=0xbfba3cec) at /home/kubo/kde4/build/qt-copy/src/corelib/kernel/qobject.cpp:3143
#15 0xa81a9d43 in TaskManager::TaskManager::taskRemoved (this=0x895ffa0, _t1={d = 0xbfba3d24})
    at /home/kubo/kde4/build/build/kdebase/workspace/libs/taskmanager/taskmanager.moc:159
#16 0xa81aabde in TaskManager::TaskManager::windowRemoved (this=0x895ffa0, w=35805372)
    at /home/kubo/kde4/build/kdebase/workspace/libs/taskmanager/taskmanager.cpp:265
#17 0xa81ab41c in TaskManager::TaskManager::qt_metacall (this=0x895ffa0,
    _c=QMetaObject::InvokeMetaMethod, _id=7, _a=0xbfba3e6c)
    at /home/kubo/kde4/build/build/kdebase/workspace/libs/taskmanager/taskmanager.moc:108
#18 0xb66a45a7 in QMetaObject::activate (sender=0x875e3c8, from_signal_index=6,
    to_signal_index=6, argv=0xbfba3e6c)
    at /home/kubo/kde4/build/qt-copy/src/corelib/kernel/qobject.cpp:3066
#19 0xb66a5973 in QMetaObject::activate (sender=0x875e3c8, m=0xb788a4cc, local_signal_index=2,
    argv=0xbfba3e6c) at /home/kubo/kde4/build/qt-copy/src/corelib/kernel/qobject.cpp:3143
#20 0xb7815b53 in KWindowSystem::windowRemoved (this=0x875e3c8, _t1=35805372)
    at /home/kubo/kde4/build/build/kdelibs/kdeui/kwindowsystem.moc:127
#21 0xb78185da in KWindowSystemPrivate::removeClient (this=0x86dde40, w=35805372)
    at /home/kubo/kde4/build/kdelibs/kdeui/windowmanagement/kwindowsystem_x11.cpp:249
#22 0xb78252c2 in NETRootInfo::update (this=0x86dde54, dirty_props=0xbfba4008)
    at /home/kubo/kde4/build/kdelibs/kdeui/windowmanagement/netwm.cpp:2130
#23 0xb78265da in NETRootInfo::event (this=0x86dde54, event=0xbfba4680, properties=0xbfba4084,
    properties_size=5) at /home/kubo/kde4/build/kdelibs/kdeui/windowmanagement/netwm.cpp:2053
#24 0xb7818695 in KWindowSystemPrivate::x11Event (this=0x86dde40, ev=0xbfba4620)
    at /home/kubo/kde4/build/kdelibs/kdeui/windowmanagement/kwindowsystem_x11.cpp:136
#25 0xb76e79fb in KAppX11HackWidget::publicx11Event (this=0x86dde40, e=0xbfba4620)
    at /home/kubo/kde4/build/kdelibs/kdeui/kernel/kapplication.cpp:935
#26 0xb76e497a in KApplication::x11EventFilter (this=0x8562720, _event=0xbfba4620)
    at /home/kubo/kde4/build/kdelibs/kdeui/kernel/kapplication.cpp:985
#27 0xb7f5911c in PlasmaApp::x11EventFilter (this=0x8562720, event=0xbfba4620)
    at /home/kubo/kde4/build/kdebase/workspace/plasma/shells/desktop/plasmaapp.cpp:426
#28 0xb6990589 in qt_x11EventFilter (ev=0xbfba4620)
    at /home/kubo/kde4/build/qt-copy/src/gui/kernel/qapplication_x11.cpp:375
#29 0xb6992df9 in QApplication::x11ProcessEvent (this=0x8562720, event=0xbfba4620)
    at /home/kubo/kde4/build/qt-copy/src/gui/kernel/qapplication_x11.cpp:3273
#30 0xb69be215 in x11EventSourceDispatch (s=0x8573e70, callback=0, user_data=0x0)
    at /home/kubo/kde4/build/qt-copy/src/gui/kernel/qguieventdispatcher_glib.cpp:146
#31 0xb51f25e8 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#32 0xb51f5b4b in g_main_context_iterate () from /usr/lib/libglib-2.0.so.0
#33 0xb51f5cc8 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#34 0xb66bce82 in QEventDispatcherGlib::processEvents (this=0x856a810, flags={i = -1078310936})
    at /home/kubo/kde4/build/qt-copy/src/corelib/kernel/qeventdispatcher_glib.cpp:323
#35 0xb69bda30 in QGuiEventDispatcherGlib::processEvents (this=0x856a810, flags=
      {i = -1078310888})
    at /home/kubo/kde4/build/qt-copy/src/gui/kernel/qguieventdispatcher_glib.cpp:202
#36 0xb668b158 in QEventLoop::processEvents (this=0xbfba48a0, flags={i = -1078310816})
    at /home/kubo/kde4/build/qt-copy/src/corelib/kernel/qeventloop.cpp:149
#37 0xb668b3b2 in QEventLoop::exec (this=0xbfba48a0, flags={i = -1078310744})
    at /home/kubo/kde4/build/qt-copy/src/corelib/kernel/qeventloop.cpp:196
#38 0xb668e94b in QCoreApplication::exec ()
    at /home/kubo/kde4/build/qt-copy/src/corelib/kernel/qcoreapplication.cpp:880
#39 0xb6910584 in QApplication::exec ()
    at /home/kubo/kde4/build/qt-copy/src/gui/kernel/qapplication.cpp:3553
#40 0xb7f44cb1 in kdemain (argc=1, argv=0xbfba4a64)
    at /home/kubo/kde4/build/kdebase/workspace/plasma/shells/desktop/main.cpp:50
#41 0x08048762 in main (argc=Cannot access memory at address 0x0
)
    at /home/kubo/kde4/build/build/kdebase/workspace/plasma/shells/desktop/plasma-desktop_dummy.cpp:3