Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.00 (KDE 4.3.0)
Qt Version: 4.5.2
Operating System: Linux 2.6.28-14-generic x86_64
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
Watching VLC I switched from virtual desktop 2 to 1, and plasma-desktop crashed. I switched desktops using scroll wheel on empty desktop.

 -- Backtrace:
Application: Plasma Workspace (plasma-desktop), signal: Segmentation fault
[Current thread is 0 (LWP 9635)]

Thread 2 (Thread 0x7fd45b0c9950 (LWP 9636)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:261
#1  0x00007fd477a88d19 in QWaitCondition::wait (this=0x1d339e0, mutex=0x1d339d8, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:87
#2  0x00007fd47afe181c in QHostInfoAgent::run (this=0x1d339c0) at kernel/qhostinfo.cpp:260
#3  0x00007fd477a87d35 in QThreadPrivate::start (arg=0x1d339c0) at thread/qthread_unix.cpp:188
#4  0x00007fd4742383ba in start_thread (arg=<value optimized out>) at pthread_create.c:297
#5  0x00007fd476ff2fcd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fd47c5d8790 (LWP 9635)):
[KCrash Handler]
#5  AbstractTaskItem::basicPreferredSize (this=0x38311a0) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/tasks.h:92
#6  0x00007fd45f377d13 in TaskItemLayout::layoutItems (this=0x1ae6f70) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/taskitemlayout.cpp:273
#7  0x00007fd45f3787f4 in TaskItemLayout::insert (this=0x1ae6f70, index=1, item=0x151c8b0) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/taskitemlayout.cpp:125
#8  0x00007fd45f3789d0 in TaskItemLayout::addTaskItem (this=0x1ae6f70, item=0x151c8b0) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/taskitemlayout.cpp:82
#9  0x00007fd45f384468 in TaskGroupItem::itemAdded (this=0x1ae4410, groupableItem=0x365e180) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/taskgroupitem.cpp:477
#10 0x00007fd45f384a5c in TaskGroupItem::qt_metacall (this=0x1ae4410, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff8471a9a0)
    at /build/buildd/kdebase-workspace-4.3.0/obj-x86_64-linux-gnu/plasma/applets/tasks/taskgroupitem.moc:113
#11 0x00007fd477b86ea2 in QMetaObject::activate (sender=0x1afec60, from_signal_index=<value optimized out>, to_signal_index=21, argv=0x0) at kernel/qobject.cpp:3113
#12 0x00007fd45f149cbf in TaskManager::TaskGroup::itemAdded (this=0x0, _t1=0x365e180) at /build/buildd/kdebase-workspace-4.3.0/obj-x86_64-linux-gnu/libs/taskmanager/taskgroup.moc:139
#13 0x00007fd45f14a81b in TaskManager::TaskGroup::add (this=0x1afec60, item=0x365e180) at /build/buildd/kdebase-workspace-4.3.0/libs/taskmanager/taskgroup.cpp:138
#14 0x00007fd45f130c20 in TaskManager::AbstractGroupingStrategy::closeGroup (this=0x366e350, group=0x3771fb0)
    at /build/buildd/kdebase-workspace-4.3.0/libs/taskmanager/abstractgroupingstrategy.cpp:168
#15 0x00007fd45f137f98 in TaskManager::ProgramGroupingStrategy::checkGroup (this=0x366e350) at /build/buildd/kdebase-workspace-4.3.0/libs/taskmanager/strategies/programgroupingstrategy.cpp:204
#16 0x00007fd45f138e1d in TaskManager::ProgramGroupingStrategy::qt_metacall (this=0x366e350, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=<value optimized out>)
    at /build/buildd/kdebase-workspace-4.3.0/obj-x86_64-linux-gnu/libs/taskmanager/programgroupingstrategy.moc:68
#17 0x00007fd477b86ea2 in QMetaObject::activate (sender=0x3771fb0, from_signal_index=<value optimized out>, to_signal_index=22, argv=0x0) at kernel/qobject.cpp:3113
#18 0x00007fd45f149c82 in TaskManager::TaskGroup::itemRemoved (this=0x0, _t1=0x1b58670) at /build/buildd/kdebase-workspace-4.3.0/obj-x86_64-linux-gnu/libs/taskmanager/taskgroup.moc:146
#19 0x00007fd45f14a5a1 in TaskManager::TaskGroup::remove (this=0x3771fb0, item=0x1b58670) at /build/buildd/kdebase-workspace-4.3.0/libs/taskmanager/taskgroup.cpp:182
#20 0x00007fd45f133aa4 in TaskManager::GroupManagerPrivate::removeTask (this=0x1a881e0, task={d = 0x7fff8471acc0}) at /build/buildd/kdebase-workspace-4.3.0/libs/taskmanager/groupmanager.cpp:311
#21 0x00007fd45f133fde in TaskManager::GroupManagerPrivate::actuallyReloadTasks (this=0x1a881e0) at /build/buildd/kdebase-workspace-4.3.0/libs/taskmanager/groupmanager.cpp:164
#22 0x00007fd45f135262 in TaskManager::GroupManager::qt_metacall (this=0x16cce20, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff8471ae40)
    at /build/buildd/kdebase-workspace-4.3.0/obj-x86_64-linux-gnu/libs/taskmanager/groupmanager.moc:108
#23 0x00007fd477b86ea2 in QMetaObject::activate (sender=0x1a88248, from_signal_index=<value optimized out>, to_signal_index=4, argv=0x0) at kernel/qobject.cpp:3113
#24 0x00007fd477b81263 in QObject::event (this=0x1a88248, e=0x7fd477049528) at kernel/qobject.cpp:1075
#25 0x00007fd47827af4d in QApplicationPrivate::notify_helper (this=0x11bc300, receiver=0x1a88248, e=0x7fff8471b4f0) at kernel/qapplication.cpp:4056
#26 0x00007fd47828318a in QApplication::notify (this=0x11a1c80, receiver=0x1a88248, e=0x7fff8471b4f0) at kernel/qapplication.cpp:4021
#27 0x00007fd47a91e71b in KApplication::notify (this=0x11a1c80, receiver=0x1a88248, event=0x7fff8471b4f0) at /build/buildd/kde4libs-4.3.0/kdeui/kernel/kapplication.cpp:302
#28 0x00007fd477b716ac in QCoreApplication::notifyInternal (this=0x11a1c80, receiver=0x1a88248, event=0x7fff8471b4f0) at kernel/qcoreapplication.cpp:610
#29 0x00007fd477b9e516 in QTimerInfoList::activateTimers (this=0x11bfa60) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#30 0x00007fd477b9ab2d in timerSourceDispatch (source=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:165
#31 0x00007fd47260820a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#32 0x00007fd47260b8e0 in ?? () from /usr/lib/libglib-2.0.so.0
#33 0x00007fd47260ba7c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#34 0x00007fd477b9aa8f in QEventDispatcherGlib::processEvents (this=0x1189e70, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#35 0x00007fd478313bdf in QGuiEventDispatcherGlib::processEvents (this=0x0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#36 0x00007fd477b6ff42 in QEventLoop::processEvents (this=<value optimized out>, flags={i = -2072922272}) at kernel/qeventloop.cpp:149
#37 0x00007fd477b70314 in QEventLoop::exec (this=0x7fff8471b7a0, flags={i = -2072922192}) at kernel/qeventloop.cpp:201
#38 0x00007fd477b725e4 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#39 0x00007fd47c2b51eb in kdemain (argc=1, argv=0x7fff8471baa8) at /build/buildd/kdebase-workspace-4.3.0/plasma/shells/desktop/main.cpp:50
#40 0x00007fd476f2b5a6 in __libc_start_main (main=0x400890 <main>, argc=1, ubp_av=0x7fff8471baa8, init=0x4008c0 <__libc_csu_init>, fini=<value optimized out>, rtld_fini=<value optimized out>, 
    stack_end=0x7fff8471ba98) at libc-start.c:220
#41 0x00000000004007c9 in _start () at ../sysdeps/x86_64/elf/start.S:113

Reported using DrKonqi