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 2.6.28-15-generic x86_64
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
Plasma crashes very often when switching virtual desktops. See backtrace attached.

 -- Backtrace:
Application: Plasma Workspace (plasma-desktop), signal: Segmentation fault
[Current thread is 0 (LWP 10948)]

Thread 2 (Thread 0x7f6c177d1950 (LWP 10949)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:261
#1  0x00007f6c36c20d19 in QWaitCondition::wait (this=0x29e2a40, mutex=0x29e2a38, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:87
#2  0x00007f6c3a17981c in QHostInfoAgent::run (this=0x29e2a20) at kernel/qhostinfo.cpp:260
#3  0x00007f6c36c1fd35 in QThreadPrivate::start (arg=0x29e2a20) at thread/qthread_unix.cpp:188
#4  0x00007f6c333b53ba in start_thread (arg=<value optimized out>) at pthread_create.c:297
#5  0x00007f6c3618afcd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#6  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7f6c3b76d790 (LWP 10948)):
[KCrash Handler]
#5  AbstractTaskItem::basicPreferredSize (this=0x3a08310) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/tasks.h:92
#6  0x00007f6c1a47f256 in TaskItemLayout::preferredColumns (this=0x27b1110) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/taskitemlayout.cpp:206
#7  0x00007f6c1a47fbac in TaskItemLayout::gridLayoutSize (this=0x27b1110) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/taskitemlayout.cpp:222
#8  0x00007f6c1a47fc3b in TaskItemLayout::layoutItems (this=0x0) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/taskitemlayout.cpp:245
#9  0x00007f6c1a4807f4 in TaskItemLayout::insert (this=0x27b1110, index=5, item=0x2bd1310) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/taskitemlayout.cpp:125
#10 0x00007f6c1a4809d0 in TaskItemLayout::addTaskItem (this=0x27b1110, item=0x2bd1310) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/taskitemlayout.cpp:82
#11 0x00007f6c1a48c468 in TaskGroupItem::itemAdded (this=0x2303810, groupableItem=0x28ac440) at /build/buildd/kdebase-workspace-4.3.0/plasma/applets/tasks/taskgroupitem.cpp:477
#12 0x00007f6c1a48ca5c in TaskGroupItem::qt_metacall (this=0x2303810, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff438b4c20)
    at /build/buildd/kdebase-workspace-4.3.0/obj-x86_64-linux-gnu/plasma/applets/tasks/taskgroupitem.moc:113
#13 0x00007f6c36d1eea2 in QMetaObject::activate (sender=0x249d230, from_signal_index=<value optimized out>, to_signal_index=21, argv=0x0) at kernel/qobject.cpp:3113
#14 0x00007f6c1eb2ccbf in TaskManager::TaskGroup::itemAdded (this=0x0, _t1=0x28ac440) at /build/buildd/kdebase-workspace-4.3.0/obj-x86_64-linux-gnu/libs/taskmanager/taskgroup.moc:139
#15 0x00007f6c1eb2d81b in TaskManager::TaskGroup::add (this=0x249d230, item=0x28ac440) at /build/buildd/kdebase-workspace-4.3.0/libs/taskmanager/taskgroup.cpp:138
#16 0x00007f6c1eb1c5e3 in TaskManager::ProgramGroupingStrategy::handleItem (this=0x3d5cc70, item=0x28ac440)
    at /build/buildd/kdebase-workspace-4.3.0/libs/taskmanager/strategies/programgroupingstrategy.cpp:154
#17 0x00007f6c1eb160bd in TaskManager::GroupManagerPrivate::addTask (this=0x2334670, task={d = 0x7fff438b4d80}) at /build/buildd/kdebase-workspace-4.3.0/libs/taskmanager/groupmanager.cpp:288
#18 0x00007f6c1eb16df1 in TaskManager::GroupManagerPrivate::actuallyReloadTasks (this=0x2334670) at /build/buildd/kdebase-workspace-4.3.0/libs/taskmanager/groupmanager.cpp:155
#19 0x00007f6c1eb18262 in TaskManager::GroupManager::qt_metacall (this=0x2299ce0, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fff438b4ef0)
    at /build/buildd/kdebase-workspace-4.3.0/obj-x86_64-linux-gnu/libs/taskmanager/groupmanager.moc:108
#20 0x00007f6c36d1eea2 in QMetaObject::activate (sender=0x23346d8, from_signal_index=<value optimized out>, to_signal_index=4, argv=0x0) at kernel/qobject.cpp:3113
#21 0x00007f6c36d19263 in QObject::event (this=0x23346d8, e=0x7f6c361e1528) at kernel/qobject.cpp:1075
#22 0x00007f6c37412f4d in QApplicationPrivate::notify_helper (this=0x19f69f0, receiver=0x23346d8, e=0x7fff438b55a0) at kernel/qapplication.cpp:4056
#23 0x00007f6c3741b18a in QApplication::notify (this=0x19e2c40, receiver=0x23346d8, e=0x7fff438b55a0) at kernel/qapplication.cpp:4021
#24 0x00007f6c39ab671b in KApplication::notify (this=0x19e2c40, receiver=0x23346d8, event=0x7fff438b55a0) at /build/buildd/kde4libs-4.3.0/kdeui/kernel/kapplication.cpp:302
#25 0x00007f6c36d096ac in QCoreApplication::notifyInternal (this=0x19e2c40, receiver=0x23346d8, event=0x7fff438b55a0) at kernel/qcoreapplication.cpp:610
#26 0x00007f6c36d36516 in QTimerInfoList::activateTimers (this=0x19fa160) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#27 0x00007f6c36d32b2d in timerSourceDispatch (source=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:165
#28 0x00007f6c3178520a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#29 0x00007f6c317888e0 in ?? () from /usr/lib/libglib-2.0.so.0
#30 0x00007f6c31788a7c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#31 0x00007f6c36d32a8f in QEventDispatcherGlib::processEvents (this=0x19cae30, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#32 0x00007f6c374abbdf in QGuiEventDispatcherGlib::processEvents (this=0x0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#33 0x00007f6c36d07f42 in QEventLoop::processEvents (this=<value optimized out>, flags={i = 1133205520}) at kernel/qeventloop.cpp:149
#34 0x00007f6c36d08314 in QEventLoop::exec (this=0x7fff438b5850, flags={i = 1133205600}) at kernel/qeventloop.cpp:201
#35 0x00007f6c36d0a5e4 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#36 0x00007f6c3b44d1eb in kdemain (argc=1, argv=0x7fff438b5b58) at /build/buildd/kdebase-workspace-4.3.0/plasma/shells/desktop/main.cpp:50
#37 0x00007f6c360c35a6 in __libc_start_main (main=0x400890 <main>, argc=1, ubp_av=0x7fff438b5b58, init=0x4008c0 <__libc_csu_init>, fini=<value optimized out>, rtld_fini=<value optimized out>, 
    stack_end=0x7fff438b5b48) at libc-start.c:220
#38 0x00000000004007c9 in _start () at ../sysdeps/x86_64/elf/start.S:113

This bug may be a duplicate of or related to bug 203776

Reported using DrKonqi