Version:            (using KDE 4.2.0)
Compiler:          gcc (GCC) 4.1.2 (Gentoo 4.1.2 p1.1) 
OS:                Linux
Installed from:    Gentoo Packages

Plasma crashed while I was switching desktops (using the pager). I've only seen this once; I don't think I know how to reproduce it. I'm using KDE 4.2.0.

The first desktop had two groups of tasks, but for some reason was using two rows and there was an empty space at the beginning of the first row. The second desktop had a single konsole window open. I have it the task tray set to only display tasks from the current desktop.

Here's the stack trace:

Thread 1 (Thread 0x7f6d1c45d740 (LWP 2312)):
[KCrash Handler]
#5  Tasks::itemTopMargin (this=0x4e005f006d006f) at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace-4.2.0/plasma/applets/tasks/tasks.h:93
#6  0x00007f6d04aeeb97 in AbstractTaskItem::basicPreferredSize (this=0x2ae2650)
    at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace-4.2.0/plasma/applets/tasks/abstracttaskitem.cpp:92
#7  0x00007f6d04ae976a in LayoutWidget::preferredColumns (this=0x2837d40) at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace-4.2.0/plasma/applets/tasks/layoutwidget.cpp:212
#8  0x00007f6d04ae986a in LayoutWidget::gridLayoutSize (this=0x2837d40) at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace-4.2.0/plasma/applets/tasks/layoutwidget.cpp:228
#9  0x00007f6d04ae9919 in LayoutWidget::layoutItems (this=0x4e005f006d006f) at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace-4.2.0/plasma/applets/tasks/layoutwidget.cpp:258
#10 0x00007f6d04aea197 in LayoutWidget::insert (this=0x2837d40, index=2, item=0x2aeb290)
    at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace-4.2.0/plasma/applets/tasks/layoutwidget.cpp:125
#11 0x00007f6d04aea436 in LayoutWidget::addTaskItem (this=0x2837d40, item=0x2aeb290)
    at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace-4.2.0/plasma/applets/tasks/layoutwidget.cpp:84
#12 0x00007f6d04af31de in TaskGroupItem::itemAdded (this=0x28115c0, groupableItem=0x2a26360)
    at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace-4.2.0/plasma/applets/tasks/taskgroupitem.cpp:412
#13 0x00007f6d04af3b45 in TaskGroupItem::qt_metacall (this=0x28115c0, _c=QMetaObject::InvokeMetaMethod, _id=11, _a=0x7fff2459d2c0)
    at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace_build/plasma/applets/tasks/taskgroupitem.moc:103
#14 0x00007f6d19c3c64c in QMetaObject::activate (sender=0x2810c70, from_signal_index=<value optimized out>, to_signal_index=21, argv=0x2a82b50) at kernel/qobject.cpp:3028
#15 0x00007f6d04e34ddf in TaskManager::TaskGroup::itemAdded (this=0x4e005f006d006f, _t1=0x2a26360)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager_build/libs/taskmanager/taskgroup.moc:134
#16 0x00007f6d04e36358 in TaskManager::TaskGroup::add (this=0x2810c70, item=0x2a26360) at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager-4.2.0/libs/taskmanager/taskgroup.cpp:133
#17 0x00007f6d04e1e966 in TaskManager::AbstractGroupingStrategy::closeGroup (this=0x2ae5700, group=0x2933070)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager-4.2.0/libs/taskmanager/abstractgroupingstrategy.cpp:139
#18 0x00007f6d04e269d0 in TaskManager::ProgramGroupingStrategy::checkGroup (this=0x2ae5700)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager-4.2.0/libs/taskmanager/strategies/programgroupingstrategy.cpp:183
#19 0x00007f6d04e271dd in TaskManager::ProgramGroupingStrategy::qt_metacall (this=0x2ae5700, _c=QMetaObject::InvokeMetaMethod, _id=0, _a=<value optimized out>)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager_build/libs/taskmanager/programgroupingstrategy.moc:67
#20 0x00007f6d19c3c64c in QMetaObject::activate (sender=0x2933070, from_signal_index=<value optimized out>, to_signal_index=22, argv=0x2a82b50) at kernel/qobject.cpp:3028
#21 0x00007f6d04e34da2 in TaskManager::TaskGroup::itemRemoved (this=0x4e005f006d006f, _t1=0x283c500)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager_build/libs/taskmanager/taskgroup.moc:141
#22 0x00007f6d04e360e9 in TaskManager::TaskGroup::remove (this=0x2933070, item=0x283c500)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager-4.2.0/libs/taskmanager/taskgroup.cpp:171
#23 0x00007f6d04e217c5 in TaskManager::GroupManager::remove (this=0x2716980, task=<value optimized out>)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager-4.2.0/libs/taskmanager/groupmanager.cpp:283
#24 0x00007f6d04e21fe4 in TaskManager::GroupManagerPrivate::reloadTasks (this=0x285cb10)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager-4.2.0/libs/taskmanager/groupmanager.cpp:136
#25 0x00007f6d04e2280f in TaskManager::GroupManager::qt_metacall (this=0x2716980, _c=QMetaObject::InvokeMetaMethod, _id=8, _a=0x7fff2459d850)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager_build/libs/taskmanager/groupmanager.moc:96
#26 0x00007f6d19c3c64c in QMetaObject::activate (sender=0x2713000, from_signal_index=<value optimized out>, to_signal_index=8, argv=0x2a82b50) at kernel/qobject.cpp:3028
#27 0x00007f6d04e37df1 in TaskManager::TaskManager::desktopChanged (this=0x4e005f006d006f, _t1=2)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager_build/libs/taskmanager/taskmanager.moc:178
#28 0x00007f6d04e39220 in TaskManager::TaskManager::qt_metacall (this=0x2713000, _c=QMetaObject::InvokeMetaMethod, _id=10, _a=0x7fff2459da00)
    at /var/tmp/portage/kde-base/libtaskmanager-4.2.0/work/libtaskmanager_build/libs/taskmanager/taskmanager.moc:110
#29 0x00007f6d19c3c64c in QMetaObject::activate (sender=0x26b0f80, from_signal_index=<value optimized out>, to_signal_index=4, argv=0x2a82b50) at kernel/qobject.cpp:3028
#30 0x00007f6d1a8d73ee in KWindowSystem::currentDesktopChanged (this=0x4e005f006d006f, _t1=2) at /var/tmp/portage/kde-base/kdelibs-4.2.0/work/kdelibs_build/kdeui/kwindowsystem.moc:111
#31 0x00007f6d1a8d9c50 in KWindowSystemPrivate::x11Event (this=0x2678450, ev=0x7fff2459e150)
    at /var/tmp/portage/kde-base/kdelibs-4.2.0/work/kdelibs-4.2.0/kdeui/windowmanagement/kwindowsystem_x11.cpp:139
#32 0x00007f6d1a7dadad in KAppX11HackWidget::publicx11Event (this=0x4e005f006d006f, e=0x7f6d17f5cf38) at /var/tmp/portage/kde-base/kdelibs-4.2.0/work/kdelibs-4.2.0/kdeui/kernel/kapplication.cpp:935
#33 0x00007f6d1a7d7fb6 in KApplication::x11EventFilter (this=<value optimized out>, _event=0x7fff2459e150)
    at /var/tmp/portage/kde-base/kdelibs-4.2.0/work/kdelibs-4.2.0/kdeui/kernel/kapplication.cpp:985
#34 0x00007f6d1c150b88 in PlasmaApp::x11EventFilter (this=0x2538040, event=0x7fff2459e150)
    at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace-4.2.0/plasma/shells/desktop/plasmaapp.cpp:453
#35 0x00007f6d18d3b04f in qt_x11EventFilter () from /usr/lib64/qt4/libQtGui.so.4
#36 0x00007f6d18d47a07 in QApplication::x11ProcessEvent () from /usr/lib64/qt4/libQtGui.so.4
#37 0x00007f6d18d6bfd5 in QEventDispatcherX11::processEvents () from /usr/lib64/qt4/libQtGui.so.4
#38 0x00007f6d19c26265 in QEventLoop::processEvents (this=<value optimized out>, flags=@0x7fff2459e360) at kernel/qeventloop.cpp:149
#39 0x00007f6d19c263ca in QEventLoop::exec (this=0x7fff2459e3a0, flags=@0x7fff2459e3b0) at kernel/qeventloop.cpp:200
#40 0x00007f6d19c2850e in QCoreApplication::exec () at kernel/qcoreapplication.cpp:851
#41 0x00007f6d1c1411fb in kdemain (argc=1, argv=0x7fff2459e6c8) at /var/tmp/portage/kde-base/plasma-workspace-4.2.0/work/plasma-workspace-4.2.0/plasma/shells/desktop/main.cpp:54
#42 0x00007f6d17e6fb74 in __libc_start_main () from /lib/libc.so.6
#43 0x0000000000400929 in _start ()