Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.2.90 (KDE 4.2.90 (KDE 4.3 Beta2))
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:
open thunderbird and close new email

 -- Backtrace:
Application: Plasma Workspace (kdeinit), signal: Segmentation fault
[Current thread is 0 (LWP 3972)]

Thread 2 (Thread 0xa775ab90 (LWP 3976)):
#0  0xb7f04430 in __kernel_vsyscall ()
#1  0xb63cc0e5 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb65ac2ed in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0xb7cff9b2 in QWaitCondition::wait (this=0x8d60678, mutex=0x8d60674, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  0xb763b152 in QHostInfoAgent::run (this=0x8d60668) at kernel/qhostinfo.cpp:260
#5  0xb7cfe96e in QThreadPrivate::start (arg=0x8d60668) at thread/qthread_unix.cpp:189
#6  0xb63c84ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb659d49e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb5ed6a10 (LWP 3972)):
[KCrash Handler]
#6  0xa81a507e in TaskManager::AbstractGroupingStrategy::closeGroup () from /usr/lib/libtaskmanager.so.4
#7  0xa81aca47 in ?? () from /usr/lib/libtaskmanager.so.4
#8  0xa81ad6eb in ?? () from /usr/lib/libtaskmanager.so.4
#9  0xb7e08ca8 in QMetaObject::activate (sender=0x8dad200, from_signal_index=22, to_signal_index=22, argv=0xbfd211dc) at kernel/qobject.cpp:3069
#10 0xb7e09932 in QMetaObject::activate (sender=0x8dad200, m=0xa81ceb74, local_signal_index=1, argv=0xbfd211dc) at kernel/qobject.cpp:3143
#11 0xa81c07f3 in TaskManager::TaskGroup::itemRemoved () from /usr/lib/libtaskmanager.so.4
#12 0xa81c0e40 in TaskManager::TaskGroup::remove () from /usr/lib/libtaskmanager.so.4
#13 0xa81a7cd5 in ?? () from /usr/lib/libtaskmanager.so.4
#14 0xa81a9e2a in TaskManager::GroupManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#15 0xb7e08ca8 in QMetaObject::activate (sender=0x8c22170, from_signal_index=5, to_signal_index=5, argv=0xbfd2135c) at kernel/qobject.cpp:3069
#16 0xb7e09932 in QMetaObject::activate (sender=0x8c22170, m=0xa81ced3c, local_signal_index=1, argv=0xbfd2135c) at kernel/qobject.cpp:3143
#17 0xa81c4003 in TaskManager::TaskManager::taskRemoved () from /usr/lib/libtaskmanager.so.4
#18 0xa81c5767 in TaskManager::TaskManager::windowRemoved () from /usr/lib/libtaskmanager.so.4
#19 0xa81c7814 in TaskManager::TaskManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#20 0xb7e08ca8 in QMetaObject::activate (sender=0x891e708, from_signal_index=6, to_signal_index=6, argv=0xbfd214cc) at kernel/qobject.cpp:3069
#21 0xb7e09932 in QMetaObject::activate (sender=0x891e708, m=0xb757126c, local_signal_index=2, argv=0xbfd214cc) at kernel/qobject.cpp:3143
#22 0xb7509243 in KWindowSystem::windowRemoved (this=0x891e708, _t1=56639855) at /build/buildd/kde4libs-4.2.90/obj-i486-linux-gnu/kdeui/kwindowsystem.moc:127
#23 0xb750bac6 in KWindowSystemPrivate::removeClient (this=0x88f8668, w=56639855) at /build/buildd/kde4libs-4.2.90/kdeui/windowmanagement/kwindowsystem_x11.cpp:249
#24 0xb751b1a2 in NETRootInfo::update (this=0x88f867c, dirty_props=0xbfd21614) at /build/buildd/kde4libs-4.2.90/kdeui/windowmanagement/netwm.cpp:2126
#25 0xb751b51f in NETRootInfo::event (this=0x88f867c, event=0xbfd21d2c, properties=0xbfd216f8, properties_size=5) at /build/buildd/kde4libs-4.2.90/kdeui/windowmanagement/netwm.cpp:2053
#26 0xb750bd5d in KWindowSystemPrivate::x11Event (this=0x88f8668, ev=0xbfd21ccc) at /build/buildd/kde4libs-4.2.90/kdeui/windowmanagement/kwindowsystem_x11.cpp:136
#27 0xb73bc1a9 in KApplication::x11EventFilter (this=0x8769320, _event=0xbfd21ccc) at /build/buildd/kde4libs-4.2.90/kdeui/kernel/kapplication.cpp:911
#28 0xb3ae5c97 in ?? () from /usr/lib/libkdeinit4_plasma-desktop.so
#29 0xb68e5f3e in qt_x11EventFilter (ev=0xbfd21ccc) at kernel/qapplication_x11.cpp:375
#30 0xb68f86a8 in QApplication::x11ProcessEvent (this=0x8769320, event=0xbfd21ccc) at kernel/qapplication_x11.cpp:3273
#31 0xb6924c6a in x11EventSourceDispatch (s=0x879d000, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#32 0xb6415b88 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#33 0xb64190eb in ?? () from /usr/lib/libglib-2.0.so.0
#34 0xb6419268 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#35 0xb7e1e438 in QEventDispatcherGlib::processEvents (this=0x87994a0, flags={i = -1076748664}) at kernel/qeventdispatcher_glib.cpp:323
#36 0xb6924365 in QGuiEventDispatcherGlib::processEvents (this=0x87994a0, flags={i = -1076748616}) at kernel/qguieventdispatcher_glib.cpp:202
#37 0xb7df106a in QEventLoop::processEvents (this=0xbfd21f30, flags={i = -1076748552}) at kernel/qeventloop.cpp:149
#38 0xb7df14aa in QEventLoop::exec (this=0xbfd21f30, flags={i = -1076748488}) at kernel/qeventloop.cpp:200
#39 0xb7df3959 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:880
#40 0xb6882d17 in QApplication::exec () at kernel/qapplication.cpp:3553
#41 0xb3ad0820 in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#42 0x0804e1c0 in launch (argc=1, _name=0x876d76c "/usr/bin/plasma-desktop", args=0x876d784 "", cwd=0x0, envc=0, envs=0x876d788 "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x80512d0 "0") at /build/buildd/kde4libs-4.2.90/kinit/kinit.cpp:671
#43 0x0804e99d in handle_launcher_request (sock=7, who=<value optimized out>) at /build/buildd/kde4libs-4.2.90/kinit/kinit.cpp:1163
#44 0x0804ef25 in handle_requests (waitForPid=0) at /build/buildd/kde4libs-4.2.90/kinit/kinit.cpp:1356
#45 0x0804fb0a in main (argc=2, argv=0xbfd22724, envp=0xbfd22730) at /build/buildd/kde4libs-4.2.90/kinit/kinit.cpp:1783

Reported using DrKonqi