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:
Switched Firefox Window/Tab after leaving Plasma Widget File System Viewer.  Crash reporting assistant appeared over Plasma Desktop.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 0 (LWP 4677)]

Thread 2 (Thread 0xa82b1b90 (LWP 4679)):
#0  0xb7f05430 in __kernel_vsyscall ()
#1  0xb63c90e5 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb65a92ed in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0xb7cfc9b2 in QWaitCondition::wait (this=0x92158e8, mutex=0x92158e4, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  0xb7638152 in QHostInfoAgent::run (this=0x92158d8) at kernel/qhostinfo.cpp:260
#5  0xb7cfb96e in QThreadPrivate::start (arg=0x92158d8) at thread/qthread_unix.cpp:189
#6  0xb63c54ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb659a49e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb5ed3a10 (LWP 4677)):
[KCrash Handler]
#6  0xa846c32a in TaskManager::GroupManager::manualSortingRequest () from /usr/lib/libtaskmanager.so.4
#7  0xa846a31b in TaskManager::AbstractGroupingStrategy::closeGroup () from /usr/lib/libtaskmanager.so.4
#8  0xa8471f27 in ?? () from /usr/lib/libtaskmanager.so.4
#9  0xa8472e5b in ?? () from /usr/lib/libtaskmanager.so.4
#10 0xb7e05ca8 in QMetaObject::activate (sender=0x9ec71d8, from_signal_index=22, to_signal_index=22, argv=0xbfb2180c) at kernel/qobject.cpp:3069
#11 0xb7e06932 in QMetaObject::activate (sender=0x9ec71d8, m=0xa8494b74, local_signal_index=1, argv=0xbfb2180c) at kernel/qobject.cpp:3143
#12 0xa8485d83 in TaskManager::TaskGroup::itemRemoved () from /usr/lib/libtaskmanager.so.4
#13 0xa84867ab in TaskManager::TaskGroup::remove () from /usr/lib/libtaskmanager.so.4
#14 0xa846cba5 in ?? () from /usr/lib/libtaskmanager.so.4
#15 0xa846f46a in TaskManager::GroupManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#16 0xb7e05ca8 in QMetaObject::activate (sender=0x8f36568, from_signal_index=5, to_signal_index=5, argv=0xbfb2199c) at kernel/qobject.cpp:3069
#17 0xb7e06932 in QMetaObject::activate (sender=0x8f36568, m=0xa8494d3c, local_signal_index=1, argv=0xbfb2199c) at kernel/qobject.cpp:3143
#18 0xa8489823 in TaskManager::TaskManager::taskRemoved () from /usr/lib/libtaskmanager.so.4
#19 0xa848b0cf in TaskManager::TaskManager::windowRemoved () from /usr/lib/libtaskmanager.so.4
#20 0xa848cfec in TaskManager::TaskManager::qt_metacall () from /usr/lib/libtaskmanager.so.4
#21 0xb7e05ca8 in QMetaObject::activate (sender=0x8e63c98, from_signal_index=6, to_signal_index=6, argv=0xbfb21b0c) at kernel/qobject.cpp:3069
#22 0xb7e06932 in QMetaObject::activate (sender=0x8e63c98, m=0xb756e26c, local_signal_index=2, argv=0xbfb21b0c) at kernel/qobject.cpp:3143
#23 0xb7506853 in KWindowSystem::windowRemoved (this=0x8e63c98, _t1=60817639) at /build/buildd/kde4libs-4.2.95/obj-i486-linux-gnu/kdeui/kwindowsystem.moc:127
#24 0xb75090d6 in KWindowSystemPrivate::removeClient (this=0x8cfc580, w=60817639) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/kwindowsystem_x11.cpp:249
#25 0xb7518753 in NETRootInfo::update (this=0x8cfc594, dirty_props=0xbfb21c54) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/netwm.cpp:2135
#26 0xb7518b3f in NETRootInfo::event (this=0x8cfc594, event=0xbfb2236c, properties=0xbfb21d38, properties_size=5) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/netwm.cpp:2058
#27 0xb750936d in KWindowSystemPrivate::x11Event (this=0x8cfc580, ev=0xbfb2230c) at /build/buildd/kde4libs-4.2.95/kdeui/windowmanagement/kwindowsystem_x11.cpp:136
#28 0xb73b96f9 in KApplication::x11EventFilter (this=0x8bc3598, _event=0xbfb2230c) at /build/buildd/kde4libs-4.2.95/kdeui/kernel/kapplication.cpp:911
#29 0xb3adde37 in ?? () from /usr/lib/libkdeinit4_plasma-desktop.so
#30 0xb68e2f3e in qt_x11EventFilter (ev=0xbfb2230c) at kernel/qapplication_x11.cpp:375
#31 0xb68f56a8 in QApplication::x11ProcessEvent (this=0x8bc3598, event=0xbfb2230c) at kernel/qapplication_x11.cpp:3273
#32 0xb6921c6a in x11EventSourceDispatch (s=0x8bcc2b0, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#33 0xb6412b88 in IA__g_main_context_dispatch (context=0x8bcb698) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:1814
#34 0xb64160eb in g_main_context_iterate (context=0x8bcb698, block=1, dispatch=1, self=0x8bc9018) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:2448
#35 0xb6416268 in IA__g_main_context_iteration (context=0x8bcb698, may_block=1) at /build/buildd/glib2.0-2.20.1/glib/gmain.c:2511
#36 0xb7e1b438 in QEventDispatcherGlib::processEvents (this=0x8bc6d60, flags={i = -1078844216}) at kernel/qeventdispatcher_glib.cpp:323
#37 0xb6921365 in QGuiEventDispatcherGlib::processEvents (this=0x8bc6d60, flags={i = -1078844168}) at kernel/qguieventdispatcher_glib.cpp:202
#38 0xb7dee06a in QEventLoop::processEvents (this=0xbfb22570, flags={i = -1078844104}) at kernel/qeventloop.cpp:149
#39 0xb7dee4aa in QEventLoop::exec (this=0xbfb22570, flags={i = -1078844040}) at kernel/qeventloop.cpp:200
#40 0xb7df0959 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:880
#41 0xb687fd17 in QApplication::exec () at kernel/qapplication.cpp:3553
#42 0xb3ac8510 in kdemain () from /usr/lib/libkdeinit4_plasma-desktop.so
#43 0x0804e1c0 in launch (argc=1, _name=0x8bb021c "/usr/bin/plasma-desktop", args=0x8bb0234 "", cwd=0x0, envc=0, envs=0x8bb0238 "", 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=0xbfb22d64, envp=0xbfb22d70) at /build/buildd/kde4libs-4.2.95/kinit/kinit.cpp:1784

Reported using DrKonqi