Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.2.95 (KDE 4.2.95 (KDE 4.3 RC1))
Qt Version: 4.5.0
Operating System: Linux 2.6.30-020630-generic x86_64
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
Plasma crashes randomly (i.e. could not determine any patern how this happens) when closing application windows.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 0 (LWP 3674)]

Thread 2 (Thread 0x7feaa7950950 (LWP 3690)):
#0  0x00007feac2ff72e9 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007feac7172939 in QWaitCondition::wait () from /usr/lib/libQtCore.so.4
#2  0x00007feac5fef4cc in ?? () from /usr/lib/libQtNetwork.so.4
#3  0x00007feac7171952 in ?? () from /usr/lib/libQtCore.so.4
#4  0x00007feac2ff33ba in start_thread () from /lib/libpthread.so.0
#5  0x00007feac3bd7fcd in clone () from /lib/libc.so.6
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7feac7737750 (LWP 3674)):
[KCrash Handler]
#4  0x00007feaaa449766 in TaskManager::GroupManager::manualSortingRequest () from /usr/lib/libtaskmanager.so.4
#5  0x00007feaaa447b3a in TaskManager::AbstractGroupingStrategy::closeGroup () from /usr/lib/libtaskmanager.so.4
#6  0x00007feaaa44eda8 in ?? () from /usr/lib/libtaskmanager.so.4
#7  0x00007feaaa44fc2d in ?? () from /usr/lib/libtaskmanager.so.4
#8  0x00007feac72701f2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#9  0x00007feaaa460a92 in TaskManager::TaskGroup::itemRemoved () from /usr/lib/libtaskmanager.so.4
#10 0x00007feaaa4613b1 in TaskManager::TaskGroup::remove () from /usr/lib/libtaskmanager.so.4
#11 0x00007feaaa449ed1 in ?? () from /usr/lib/libtaskmanager.so.4
#12 0x00007feaaa44c51d in TaskManager::GroupManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#13 0x00007feac72701f2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#14 0x00007feaaa463f35 in TaskManager::TaskManager::taskRemoved () from /usr/lib/libtaskmanager.so.4
#15 0x00007feaaa46556e in TaskManager::TaskManager::windowRemoved () from /usr/lib/libtaskmanager.so.4
#16 0x00007feaaa4672bf in TaskManager::TaskManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#17 0x00007feac72701f2 in QMetaObject::activate () from /usr/lib/libQtCore.so.4
#18 0x00007feac5a54ab2 in KWindowSystem::windowRemoved () from /usr/lib/libkdeui.so.5
#19 0x00007feac5a56ffb in ?? () from /usr/lib/libkdeui.so.5
#20 0x00007feac5a65fe1 in NETRootInfo::update () from /usr/lib/libkdeui.so.5
#21 0x00007feac5a6636b in NETRootInfo::event () from /usr/lib/libkdeui.so.5
#22 0x00007feac5a572cb in ?? () from /usr/lib/libkdeui.so.5
#23 0x00007feac5926a43 in KApplication::x11EventFilter () from /usr/lib/libkdeui.so.5
#24 0x00007feabbda4b57 in ?? () from /usr/lib/libkdeinit4_plasma-desktop.so
#25 0x00007feac4840b1f in ?? () from /usr/lib/libQtGui.so.4
#26 0x00007feac4853faf in QApplication::x11ProcessEvent () from /usr/lib/libQtGui.so.4
#27 0x00007feac487d464 in ?? () from /usr/lib/libQtGui.so.4
#28 0x00007feac324220a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#29 0x00007feac32458e0 in ?? () from /usr/lib/libglib-2.0.so.0
#30 0x00007feac3245a7c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#31 0x00007feac7283e6f in QEventDispatcherGlib::processEvents () from /usr/lib/libQtCore.so.4
#32 0x00007feac487cbef in ?? () from /usr/lib/libQtGui.so.4
#33 0x00007feac7259002 in QEventLoop::processEvents () from /usr/lib/libQtCore.so.4
#34 0x00007feac72593cd in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#35 0x00007feac725b694 in QCoreApplication::exec () from /usr/lib/libQtCore.so.4
#36 0x00007feabbd9163b in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#37 0x000000000040714e in _start ()

Reported using DrKonqi