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 2.6.28-13-generic i686
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
often while using thunderbird plasma crashes. Not appening in beta-2. Using Kubuntu backports

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 0 (LWP 10741)]

Thread 2 (Thread 0xa839db90 (LWP 10748)):
#0  0xb8034430 in __kernel_vsyscall ()
#1  0xb64f90e5 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb66d92ed in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0xb7e2c9b2 in QWaitCondition::wait (this=0x887ba50, mutex=0x887ba4c, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  0xb7768152 in QHostInfoAgent::run (this=0x887ba40) at kernel/qhostinfo.cpp:260
#5  0xb7e2b96e in QThreadPrivate::start (arg=0x887ba40) at thread/qthread_unix.cpp:189
#6  0xb64f54ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb66ca49e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb6003a10 (LWP 10741)):
[KCrash Handler]
#6  0xa865f32a in TaskManager::GroupManager::manualSortingRequest () from /usr/lib/libtaskmanager.so.4
#7  0xa865d31b in TaskManager::AbstractGroupingStrategy::closeGroup () from /usr/lib/libtaskmanager.so.4
#8  0xa8664f27 in ?? () from /usr/lib/libtaskmanager.so.4
#9  0xa8665e5b in ?? () from /usr/lib/libtaskmanager.so.4
#10 0xb7f35ca8 in QMetaObject::activate (sender=0x94bcf18, from_signal_index=22, to_signal_index=22, argv=0xbfc4f19c) at kernel/qobject.cpp:3069
#11 0xb7f36932 in QMetaObject::activate (sender=0x94bcf18, m=0xa8687b74, local_signal_index=1, argv=0xbfc4f19c) at kernel/qobject.cpp:3143
#12 0xa8678d83 in TaskManager::TaskGroup::itemRemoved () from /usr/lib/libtaskmanager.so.4
#13 0xa86797ab in TaskManager::TaskGroup::remove () from /usr/lib/libtaskmanager.so.4
#14 0xa865fba5 in ?? () from /usr/lib/libtaskmanager.so.4
#15 0xa866246a in TaskManager::GroupManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#16 0xb7f35ca8 in QMetaObject::activate (sender=0x8864750, from_signal_index=5, to_signal_index=5, argv=0xbfc4f32c) at kernel/qobject.cpp:3069
#17 0xb7f36932 in QMetaObject::activate (sender=0x8864750, m=0xa8687d3c, local_signal_index=1, argv=0xbfc4f32c) at kernel/qobject.cpp:3143
#18 0xa867c823 in TaskManager::TaskManager::taskRemoved () from /usr/lib/libtaskmanager.so.4
#19 0xa867e0cf in TaskManager::TaskManager::windowRemoved () from /usr/lib/libtaskmanager.so.4
#20 0xa867ffec in TaskManager::TaskManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#21 0xb7f35ca8 in QMetaObject::activate (sender=0x8399f60, from_signal_index=6, to_signal_index=6, argv=0xbfc4f49c) at kernel/qobject.cpp:3069
#22 0xb7f36932 in QMetaObject::activate (sender=0x8399f60, m=0xb769e26c, local_signal_index=2, argv=0xbfc4f49c) at kernel/qobject.cpp:3143
#23 0xb7636853 in KWindowSystem::windowRemoved (this=0x8399f60, _t1=52509875) at /build/buildd/kde4libs-4.2.95/obj-i486-linux-gnu/kdeui/kwindowsystem.moc:127
#24 0xb76390d6 in KWindowSystemPrivate::removeClient (this=0x8323338, w=52509875) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/kwindowsystem_x11.cpp:249
#25 0xb76487c2 in NETRootInfo::update (this=0x832334c, dirty_props=0xbfc4f5e4) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/netwm.cpp:2131
#26 0xb7648b3f in NETRootInfo::event (this=0x832334c, event=0xbfc4fcfc, properties=0xbfc4f6c8, properties_size=5) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/netwm.cpp:2058
#27 0xb763936d in KWindowSystemPrivate::x11Event (this=0x8323338, ev=0xbfc4fc9c) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/kwindowsystem_x11.cpp:136
#28 0xb74e96f9 in KApplication::x11EventFilter (this=0x8215588, _event=0xbfc4fc9c) at /build/buildd/kde4libs-4.2.95/kdeui/kernel/kapplication.cpp:911
#29 0xb3b03e37 in ?? () from /usr/lib/libkdeinit4_plasma-desktop.so
#30 0xb6a12f3e in qt_x11EventFilter (ev=0xbfc4fc9c) at kernel/qapplication_x11.cpp:375
#31 0xb6a256a8 in QApplication::x11ProcessEvent (this=0x8215588, event=0xbfc4fc9c) at kernel/qapplication_x11.cpp:3273
#32 0xb6a51c6a in x11EventSourceDispatch (s=0x821e170, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#33 0xb6542b88 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#34 0xb65460eb in ?? () from /usr/lib/libglib-2.0.so.0
#35 0xb6546268 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#36 0xb7f4b438 in QEventDispatcherGlib::processEvents (this=0x8218c00, flags={i = -1077608872}) at kernel/qeventdispatcher_glib.cpp:323
#37 0xb6a51365 in QGuiEventDispatcherGlib::processEvents (this=0x8218c00, flags={i = -1077608824}) at kernel/qguieventdispatcher_glib.cpp:202
#38 0xb7f1e06a in QEventLoop::processEvents (this=0xbfc4ff00, flags={i = -1077608760}) at kernel/qeventloop.cpp:149
#39 0xb7f1e4aa in QEventLoop::exec (this=0xbfc4ff00, flags={i = -1077608696}) at kernel/qeventloop.cpp:200
#40 0xb7f20959 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:880
#41 0xb69afd17 in QApplication::exec () at kernel/qapplication.cpp:3553
#42 0xb3aee510 in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#43 0x0804e1c0 in launch (argc=1, _name=0x81e2b5c "/usr/bin/plasma-desktop", args=0x81e2b74 "", cwd=0x0, envc=0, envs=0x81e2b78 "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x80512d1 "0") at /build/buildd/kde4libs-4.2.95/kinit/kinit.cpp:672
#44 0x0804e99d in handle_launcher_request (sock=7, who=<value optimized out>) at /build/buildd/kde4libs-4.2.95/kinit/kinit.cpp:1164
#45 0x0804ef25 in handle_requests (waitForPid=0) at /build/buildd/kde4libs-4.2.95/kinit/kinit.cpp:1357
#46 0x0804fb0a in main (argc=2, argv=0xbfc506f4, envp=0xbfc50700) at /build/buildd/kde4libs-4.2.95/kinit/kinit.cpp:1784

Reported using DrKonqi