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:
It crashes when closing apps that changes the number of objects in the panel.
It can be reproduced by closing every application, like thinderbird, dolphin,...

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 0 (LWP 3247)]

Thread 2 (Thread 0xa89d7b90 (LWP 3250)):
#0  0xb7eef430 in __kernel_vsyscall ()
#1  0xb63b80e5 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb65982ed in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0xb7ceb9b2 in QWaitCondition::wait (this=0xa4b3c80, mutex=0xa4b3c7c, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  0xb7627152 in QHostInfoAgent::run (this=0xa4b3c70) at kernel/qhostinfo.cpp:260
#5  0xb7cea96e in QThreadPrivate::start (arg=0xa4b3c70) at thread/qthread_unix.cpp:189
#6  0xb63b44ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb658949e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb5ec2a10 (LWP 3247)):
[KCrash Handler]
#6  0xa94a432a in TaskManager::GroupManager::manualSortingRequest () from /usr/lib/libtaskmanager.so.4
#7  0xa94a231b in TaskManager::AbstractGroupingStrategy::closeGroup () from /usr/lib/libtaskmanager.so.4
#8  0xa94a9f27 in ?? () from /usr/lib/libtaskmanager.so.4
#9  0xa94aae5b in ?? () from /usr/lib/libtaskmanager.so.4
#10 0xb7df4ca8 in QMetaObject::activate (sender=0xa387d60, from_signal_index=22, to_signal_index=22, argv=0xbfe0a6ec) at kernel/qobject.cpp:3069
#11 0xb7df5932 in QMetaObject::activate (sender=0xa387d60, m=0xa94ccb74, local_signal_index=1, argv=0xbfe0a6ec) at kernel/qobject.cpp:3143
#12 0xa94bdd83 in TaskManager::TaskGroup::itemRemoved () from /usr/lib/libtaskmanager.so.4
#13 0xa94be7ab in TaskManager::TaskGroup::remove () from /usr/lib/libtaskmanager.so.4
#14 0xa94a4ba5 in ?? () from /usr/lib/libtaskmanager.so.4
#15 0xa94a746a in TaskManager::GroupManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#16 0xb7df4ca8 in QMetaObject::activate (sender=0xa321a18, from_signal_index=5, to_signal_index=5, argv=0xbfe0a87c) at kernel/qobject.cpp:3069
#17 0xb7df5932 in QMetaObject::activate (sender=0xa321a18, m=0xa94ccd3c, local_signal_index=1, argv=0xbfe0a87c) at kernel/qobject.cpp:3143
#18 0xa94c1823 in TaskManager::TaskManager::taskRemoved () from /usr/lib/libtaskmanager.so.4
#19 0xa94c30cf in TaskManager::TaskManager::windowRemoved () from /usr/lib/libtaskmanager.so.4
#20 0xa94c4fec in TaskManager::TaskManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#21 0xb7df4ca8 in QMetaObject::activate (sender=0xa0175d8, from_signal_index=6, to_signal_index=6, argv=0xbfe0a9ec) at kernel/qobject.cpp:3069
#22 0xb7df5932 in QMetaObject::activate (sender=0xa0175d8, m=0xb755d26c, local_signal_index=2, argv=0xbfe0a9ec) at kernel/qobject.cpp:3143
#23 0xb74f5853 in KWindowSystem::windowRemoved (this=0xa0175d8, _t1=27281917) at /build/buildd/kde4libs-4.2.95/obj-i486-linux-gnu/kdeui/kwindowsystem.moc:127
#24 0xb74f80d6 in KWindowSystemPrivate::removeClient (this=0x9e33610, w=27281917) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/kwindowsystem_x11.cpp:249
#25 0xb75077c2 in NETRootInfo::update (this=0x9e33624, dirty_props=0xbfe0ab34) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/netwm.cpp:2131
#26 0xb7507b3f in NETRootInfo::event (this=0x9e33624, event=0xbfe0b24c, properties=0xbfe0ac18, properties_size=5) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/netwm.cpp:2058
#27 0xb74f836d in KWindowSystemPrivate::x11Event (this=0x9e33610, ev=0xbfe0b1ec) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/kwindowsystem_x11.cpp:136
#28 0xb73a86f9 in KApplication::x11EventFilter (this=0x9d10a80, _event=0xbfe0b1ec) at /build/buildd/kde4libs-4.2.95/kdeui/kernel/kapplication.cpp:911
#29 0xb4a30e37 in ?? () from /usr/lib/libkdeinit4_plasma-desktop.so
#30 0xb68d1f3e in qt_x11EventFilter (ev=0xbfe0b1ec) at kernel/qapplication_x11.cpp:375
#31 0xb68e46a8 in QApplication::x11ProcessEvent (this=0x9d10a80, event=0xbfe0b1ec) at kernel/qapplication_x11.cpp:3273
#32 0xb6910c6a in x11EventSourceDispatch (s=0x9d39370, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#33 0xb6401b88 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#34 0xb64050eb in ?? () from /usr/lib/libglib-2.0.so.0
#35 0xb6405268 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#36 0xb7e0a438 in QEventDispatcherGlib::processEvents (this=0x9d33e20, flags={i = -1075792984}) at kernel/qeventdispatcher_glib.cpp:323
#37 0xb6910365 in QGuiEventDispatcherGlib::processEvents (this=0x9d33e20, flags={i = -1075792936}) at kernel/qguieventdispatcher_glib.cpp:202
#38 0xb7ddd06a in QEventLoop::processEvents (this=0xbfe0b450, flags={i = -1075792872}) at kernel/qeventloop.cpp:149
#39 0xb7ddd4aa in QEventLoop::exec (this=0xbfe0b450, flags={i = -1075792808}) at kernel/qeventloop.cpp:200
#40 0xb7ddf959 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:880
#41 0xb686ed17 in QApplication::exec () at kernel/qapplication.cpp:3553
#42 0xb4a1b510 in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#43 0x0804e1c0 in launch (argc=1, _name=0x9d1b64c "/usr/bin/plasma-desktop", args=0x9d1b664 "", cwd=0x0, envc=0, envs=0x9d1b668 "", 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=0xbfe0bc44, envp=0xbfe0bc50) at /build/buildd/kde4libs-4.2.95/kinit/kinit.cpp:1784

Reported using DrKonqi