Version:            (using Devel)
Compiler:          gcc 4.0.3 
OS:                Linux
Installed from:    Compiled sources

Steps to reproduce:

1 - Starts KDE
2 - Open KSnapshot
3 - Open Dolphin
4 - Plasma crashes after Dolphin is started

Not all the times it happens, but most of the times do. I think it only happens with this combination. I have tried others, but no crashes.

Backtrace:

Application: Plasma Workspace (plasma), signal SIGSEGV
Using host libthread_db library "/lib/libthread_db.so.1".
[Current thread is 0 (LWP 5662)]

Thread 3 (Thread 0xa9f9eb90 (LWP 5681)):
#0  0xb7f0b424 in __kernel_vsyscall ()
#1  0xb6599dc4 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb66132e6 in QWaitCondition::wait (this=0x83b9cb8, mutex=0x83b9cb4, time=4294967295) at thread/qwaitcondition_unix.cpp:82
#3  0xb788e935 in QHostInfoAgent::run (this=0x83b9ca8) at kernel/qhostinfo.cpp:241
#4  0xb66123b3 in QThreadPrivate::start (arg=0x83b9ca8) at thread/qthread_unix.cpp:185
#5  0xb6596445 in start_thread () from /lib/libpthread.so.0
#6  0xb640f32e in clone () from /lib/libc.so.6

Thread 2 (Thread 0xa977cb90 (LWP 5692)):
#0  0xb7f0b424 in __kernel_vsyscall ()
#1  0xb6599dc4 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb66132e6 in QWaitCondition::wait (this=0x81e9358, mutex=0x81e9354, time=4294967295) at thread/qwaitcondition_unix.cpp:82
#3  0xaa2e7e7d in RenderThread::run (this=0x81e934c) at /var/tmp/kde-build/4.1.80/kdebase-workspace-4.1.80/plasma/wallpapers/image/renderthread.cpp:90
#4  0xb66123b3 in QThreadPrivate::start (arg=0x81e934c) at thread/qthread_unix.cpp:185
#5  0xb6596445 in start_thread () from /lib/libpthread.so.0
#6  0xb640f32e in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb55e76d0 (LWP 5662)):
[KCrash Handler]
#6  QHash<KSharedPtr<TaskManager::Startup>, TaskManager::TaskItem*>::erase (this=0x83224b0, it={i = 0x85d6fa8}) at /opt/qt-4.4.3/include/QtCore/qhash.h:809
#7  0xaa07d2d3 in TaskManager::GroupManager::add (this=0x82d22e0, task=@0xbfe27d04) at /opt/qt-4.4.3/include/QtCore/qhash.h:1007
#8  0xaa07f2eb in TaskManager::GroupManager::qt_metacall (this=0x82d22e0, _c=QMetaObject::InvokeMetaMethod, _id=2, _a=0xbfe27dec)
    at /var/tmp/kde-build/4.1.80/kdebase-workspace-4.1.80/build/libs/taskmanager/groupmanager.moc:87
#9  0xb6713d55 in QMetaObject::activate (sender=0x8415028, from_signal_index=<value optimized out>, to_signal_index=4, argv=<value optimized out>) at kernel/qobject.cpp:3028
#10 0xb6715b72 in QMetaObject::activate (sender=0x8415028, m=0x0, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3101
#11 0xaa098fa3 in TaskManager::TaskManager::taskAdded (this=0x0, _t1=@0x0) at /var/tmp/kde-build/4.1.80/kdebase-workspace-4.1.80/build/libs/taskmanager/taskmanager.moc:147
#12 0xaa09a0e4 in TaskManager::TaskManager::windowAdded (this=0x8415028, w=31457281) at /var/tmp/kde-build/4.1.80/kdebase-workspace-4.1.80/libs/taskmanager/taskmanager.cpp:255
#13 0xaa09b7d7 in TaskManager::TaskManager::qt_metacall (this=0x8415028, _c=QMetaObject::InvokeMetaMethod, _id=6, _a=0xbfe27fac)
    at /var/tmp/kde-build/4.1.80/kdebase-workspace-4.1.80/build/libs/taskmanager/taskmanager.moc:104
#14 0xb6713d55 in QMetaObject::activate (sender=0x81e32d8, from_signal_index=<value optimized out>, to_signal_index=5, argv=<value optimized out>) at kernel/qobject.cpp:3028
#15 0xb6715b72 in QMetaObject::activate (sender=0x81e32d8, m=0x0, local_signal_index=1, argv=0x0) at kernel/qobject.cpp:3101
#16 0xb77c2463 in KWindowSystem::windowAdded (this=0x0, _t1=31457281) at /var/tmp/kde-build/4.1.80/kdelibs-4.1.80/build/kdeui/kwindowsystem.moc:118
#17 0xb77c41bd in KWindowSystemPrivate::addClient (this=0x81785c0, w=31457281) at /var/tmp/kde-build/4.1.80/kdelibs-4.1.80/kdeui/windowmanagement/kwindowsystem_x11.cpp:229
#18 0xb77cf3e8 in NETRootInfo::update (this=0x81785d4, dirty_props=0xbfe281a8) at /var/tmp/kde-build/4.1.80/kdelibs-4.1.80/kdeui/windowmanagement/netwm.cpp:2123
#19 0xb77d2ebe in NETRootInfo::event (this=0x81785d4, event=0xbfe2859c, properties=0xbfe28228, properties_size=5) at /var/tmp/kde-build/4.1.80/kdelibs-4.1.80/kdeui/windowmanagement/netwm.cpp:2052
#20 0xb77c43e5 in KWindowSystemPrivate::x11Event (this=0x81785c0, ev=0xbfe2859c) at /var/tmp/kde-build/4.1.80/kdelibs-4.1.80/kdeui/windowmanagement/kwindowsystem_x11.cpp:136
#21 0xb7663cd1 in KApplication::x11EventFilter (this=0x80f6290, _event=0xbfe2859c) at /var/tmp/kde-build/4.1.80/kdelibs-4.1.80/kdeui/kernel/kapplication.cpp:945
#22 0xb7ede261 in PlasmaApp::x11EventFilter (this=0x80f6290, event=0xbfe2859c) at /var/tmp/kde-build/4.1.80/kdebase-workspace-4.1.80/plasma/shells/desktop/plasmaapp.cpp:371
#23 0xb69ba38e in qt_x11EventFilter (ev=0xbfe2859c) at kernel/qapplication_x11.cpp:361
#24 0xb69c5fb1 in QApplication::x11ProcessEvent (this=0x80f6290, event=0xbfe2859c) at kernel/qapplication_x11.cpp:2918
#25 0xb69edfac in x11EventSourceDispatch (s=0x80feeb8, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:142
#26 0xb58e727d in IA__g_main_context_dispatch (context=0x80fda78) at gmain.c:2061
#27 0xb58ea9cb in g_main_context_iterate (context=0x80fda78, block=1, dispatch=1, self=0x80fae40) at gmain.c:2694
#28 0xb58eaea7 in IA__g_main_context_iteration (context=0x80fda78, may_block=1) at gmain.c:2753
#29 0xb672815b in QEventDispatcherGlib::processEvents (this=0x80f6488, flags=@0xbfe28798) at kernel/qeventdispatcher_glib.cpp:319
#30 0xb69edb45 in QGuiEventDispatcherGlib::processEvents (this=0x80f6488, flags=@0x85cc8a8) at kernel/qguieventdispatcher_glib.cpp:198
#31 0xb66fbfa0 in QEventLoop::processEvents (this=0x0, flags=@0xbfe28808) at kernel/qeventloop.cpp:143
#32 0xb66fc1fe in QEventLoop::exec (this=0xbfe28840, flags=@0xbfe28848) at kernel/qeventloop.cpp:190
#33 0xb66fe346 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:845
#34 0xb695d187 in QApplication::exec () at kernel/qapplication.cpp:3331
#35 0xb7ecae8c in kdemain (argc=0, argv=0x0) at /var/tmp/kde-build/4.1.80/kdebase-workspace-4.1.80/plasma/shells/desktop/main.cpp:58
#36 0xb635a065 in __libc_start_main () from /lib/libc.so.6
#37 0x08048701 in _start ()