Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.1 (KDE 4.3.1)
Qt Version: 4.5.2
Operating System: Linux 2.6.30-1-amd64 x86_64
Distribution: Debian GNU/Linux unstable (sid)

What I was doing when the application crashed:
These chrashes happen rarely. Happened just trying to switch from a window to another clicking on that one, firefox being one of the two window

 -- Backtrace:
Application: Spazio di lavoro di Plasma (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0x7f9e087c3750 (LWP 4440))]

Thread 2 (Thread 0x7f9dea1f6950 (LWP 4443)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:261
#1  0x00007f9e0830a469 in QWaitConditionPrivate::wait (this=0x147c1a0, mutex=0x147c198, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:87
#2  QWaitCondition::wait (this=0x147c1a0, mutex=0x147c198, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:159
#3  0x00007f9e04706024 in QHostInfoAgent::run (this=0x147c180) at kernel/qhostinfo.cpp:260
#4  0x00007f9e08309475 in QThreadPrivate::start (arg=0x147c180) at thread/qthread_unix.cpp:188
#5  0x00007f9e05047f9a in start_thread (arg=<value optimized out>) at pthread_create.c:300
#6  0x00007f9e05c0e56d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#7  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f9e087c3750 (LWP 4440)):
[KCrash Handler]
#5  Tasks::itemTopMargin (this=0x1f1c390) at ../../../../plasma/applets/tasks/tasks.h:92
#6  AbstractTaskItem::basicPreferredSize (this=0x1f1c390) at ../../../../plasma/applets/tasks/abstracttaskitem.cpp:100
#7  0x00007f9debbb3366 in TaskItemLayout::preferredColumns (this=0x15852c0) at ../../../../plasma/applets/tasks/taskitemlayout.cpp:206
#8  0x00007f9debbb3cdc in TaskItemLayout::gridLayoutSize (this=0x15852c0) at ../../../../plasma/applets/tasks/taskitemlayout.cpp:222
#9  0x00007f9debbb3d6b in TaskItemLayout::layoutItems (this=0x3d687461702c276c) at ../../../../plasma/applets/tasks/taskitemlayout.cpp:245
#10 0x00007f9debbb4709 in TaskItemLayout::remove (this=0x15852c0, item=0x1d3b100) at ../../../../plasma/applets/tasks/taskitemlayout.cpp:136
#11 0x00007f9debbb47ae in TaskItemLayout::removeTaskItem (this=0x3d687461702c276c, item=0x7f9e05c5cbc8) at ../../../../plasma/applets/tasks/taskitemlayout.cpp:93
#12 0x00007f9debbbf6d9 in TaskGroupItem::itemRemoved (this=0x1586750, groupableItem=0x1bf3200) at ../../../../plasma/applets/tasks/taskgroupitem.cpp:521
#13 0x00007f9debbc0ae1 in TaskGroupItem::qt_metacall (this=0x1586750, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff89465f70) at ./taskgroupitem.moc:114
#14 0x00007f9e08404682 in QMetaObject::activate (sender=0x1584960, from_signal_index=<value optimized out>, to_signal_index=22, argv=0x0) at kernel/qobject.cpp:3112
#15 0x00007f9debdfa442 in TaskManager::TaskGroup::itemRemoved (this=0x3d687461702c276c, _t1=0x1bf3200) at ./taskgroup.moc:146
#16 0x00007f9debdfad51 in TaskManager::TaskGroup::remove (this=0x1584960, item=0x1bf3200) at ../../../libs/taskmanager/taskgroup.cpp:182
#17 0x00007f9debde4544 in TaskManager::GroupManagerPrivate::removeTask (this=0x15723c0, task=...) at ../../../libs/taskmanager/groupmanager.cpp:311
#18 0x00007f9debde5d7d in TaskManager::GroupManager::qt_metacall (this=0x1572f90, _c=<value optimized out>, _id=<value optimized out>, _a=0x7fff89466190) at ./groupmanager.moc:105
#19 0x00007f9e08404682 in QMetaObject::activate (sender=0x1572fb0, from_signal_index=<value optimized out>, to_signal_index=5, argv=0x0) at kernel/qobject.cpp:3112
#20 0x00007f9debdfd825 in TaskManager::TaskManager::taskRemoved (this=0x3d687461702c276c, _t1=<value optimized out>) at ./taskmanager.moc:162
#21 0x00007f9debdfee27 in TaskManager::TaskManager::windowRemoved (this=0x1572fb0, w=77594757) at ../../../libs/taskmanager/taskmanager.cpp:279
#22 0x00007f9debe00aef in TaskManager::TaskManager::qt_metacall (this=0x1572fb0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff894663b0) at ./taskmanager.moc:110
#23 0x00007f9e08404682 in QMetaObject::activate (sender=0x1150750, from_signal_index=<value optimized out>, to_signal_index=6, argv=0x0) at kernel/qobject.cpp:3112
#24 0x00007f9e070fe532 in KWindowSystem::windowRemoved (this=0x3d687461702c276c, _t1=77594757) at ./kwindowsystem.moc:127
#25 0x00007f9e071009eb in KWindowSystemPrivate::removeClient (this=0x1140b30, w=77594757) at ../../kdeui/windowmanagement/kwindowsystem_x11.cpp:249
#26 0x00007f9e0710ee27 in NETRootInfo::update (this=0x1140b58, dirty_props=<value optimized out>) at ../../kdeui/windowmanagement/netwm.cpp:2183
#27 0x00007f9e0710fb41 in NETRootInfo::event (this=0x1140b58, event=<value optimized out>, properties=0x7fff894666b0, properties_size=5) at ../../kdeui/windowmanagement/netwm.cpp:2058
#28 0x00007f9e07100cab in KWindowSystemPrivate::x11Event (this=0x1140b30, ev=0x7fff894680b0) at ../../kdeui/windowmanagement/kwindowsystem_x11.cpp:136
#29 0x00007f9e06fd38d3 in KAppX11HackWidget::publicx11Event (this=<value optimized out>, _event=0x7fff894680b0) at ../../kdeui/kernel/kapplication.cpp:900
#30 KApplication::x11EventFilter (this=<value optimized out>, _event=0x7fff894680b0) at ../../kdeui/kernel/kapplication.cpp:950
#31 0x00007f9dfd5196e4 in PlasmaApp::x11EventFilter (this=0xd51b60, event=0x7fff894680b0) at ../../../../plasma/shells/desktop/plasmaapp.cpp:490
#32 0x00007f9e063d5b6f in qt_x11EventFilter (ev=0x7fff894680b0) at kernel/qapplication_x11.cpp:375
#33 0x00007f9e063e8c8e in QApplication::x11ProcessEvent (this=0xd51b60, event=0x7fff894680b0) at kernel/qapplication_x11.cpp:3271
#34 0x00007f9e06411e9c in x11EventSourceDispatch (s=0xd5e2e0, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#35 0x00007f9e0529586a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#36 0x00007f9e05298eb8 in ?? () from /usr/lib/libglib-2.0.so.0
#37 0x00007f9e0529906c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#38 0x00007f9e08417bff in QEventDispatcherGlib::processEvents (this=0xd5a280, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#39 0x00007f9e0641164f in QGuiEventDispatcherGlib::processEvents (this=0x3d687461702c276c, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#40 0x00007f9e083edde2 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#41 0x00007f9e083ee1b4 in QEventLoop::exec (this=0x7fff894683e0, flags=...) at kernel/qeventloop.cpp:201
#42 0x00007f9e083f0424 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#43 0x00007f9dfd50626b in kdemain (argc=1, argv=0xccb7a0) at ../../../../plasma/shells/desktop/main.cpp:50
#44 0x0000000000407264 in launch (argc=1, _name=0xd095e8 "/usr/bin/plasma-desktop", args=<value optimized out>, cwd=0x0, envc=0, envs=0xd09608 "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x40a0ff "0") at ../../kinit/kinit.cpp:677
#45 0x0000000000407a28 in handle_launcher_request (sock=7, who=<value optimized out>) at ../../kinit/kinit.cpp:1169
#46 0x0000000000407fae in handle_requests (waitForPid=0) at ../../kinit/kinit.cpp:1362
#47 0x000000000040863b in main (argc=2, argv=0x7fff89469258, envp=0x7fff89469270) at ../../kinit/kinit.cpp:1793

Reported using DrKonqi