Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.2.91 (KDE 4.2.91 (KDE 4.3 >= 20090609))
Qt Version: 4.6.0
Operating System: Linux 2.6.27.23-0.1-default i686

What I was doing when the application crashed:
I started KDE for the first time with a clean user (no .kde, no /tmp/, no /var/tmp stuff)
During start, folder view is displayed, then some Akonadi pops up, starts migration tasks (two show in the task bar, I did not click them), then a notification pops up (I had no time to read it, because plasma went away at this moment)

Plasma restarted itself after this crash, and during this restart, no Akonadi stuff pops up.

I found reports with similar backtraces, but I think this one is good because it should be easy to reproduce (just clean your user and login).

 -- Backtrace:
Application: Plasma Workspace (kdeinit), signal: Segmentation fault
[Current thread is 1 (Thread 0xb5c9e710 (LWP 5309))]

Thread 2 (Thread 0xa8cf5b90 (LWP 5767)):
#0  0xffffe430 in __kernel_vsyscall ()
#1  0xb7c68c35 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb7cfa587 in QWaitCondition::wait (this=0x816f268, mutex=0x816f264, time=4294967295) at /local/git/Qt/qt/src/corelib/thread/qwaitcondition_unix.cpp:87
#3  0xb752bd22 in QHostInfoAgent::run (this=0x816f258) at /local/git/Qt/qt/src/network/kernel/qhostinfo.cpp:260
#4  0xb7cf957e in QThreadPrivate::start (arg=0x816f258) at /local/git/Qt/qt/src/corelib/thread/qthread_unix.cpp:188
#5  0xb7c651b5 in start_thread () from /lib/libpthread.so.0
#6  0xb64423be in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb5c9e710 (LWP 5309)):
[KCrash Handler]
#6  TaskManager::TaskGroup::members (this=0x0) at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/taskgroup.cpp:192
#7  0xa8f2b158 in TaskGroupItem::itemAdded (this=0x8ac9bd0, groupableItem=0x8b8d7c0) at /local/svn/kde/trunk/KDE/kdebase/workspace/plasma/applets/tasks/taskgroupitem.cpp:458
#8  0xa8f2bc87 in TaskGroupItem::qt_metacall (this=0x8ac9bd0, _c=QMetaObject::InvokeMetaMethod, _id=26, _a=0xbfd0c098) at /local/build/KDE/kdebase/workspace/plasma/applets/tasks/taskgroupitem.moc:112
#9  0xb7df9fe4 in QMetaObject::activate (sender=0x8b8d720, from_signal_index=21, to_signal_index=21, argv=0xbfd0c098) at /local/git/Qt/qt/src/corelib/kernel/qobject.cpp:3118
#10 0xb7dfab92 in QMetaObject::activate (sender=0x8b8d720, m=0xa8fabb54, local_signal_index=0, argv=0xbfd0c098) at /local/git/Qt/qt/src/corelib/kernel/qobject.cpp:3192
#11 0xa8f8cae3 in TaskManager::TaskGroup::itemAdded (this=0x8b8d720, _t1=0x8b8d7c0) at /local/build/KDE/kdebase/workspace/libs/taskmanager/taskgroup.moc:137
#12 0xa8f8e3e6 in TaskManager::TaskGroup::add (this=0x8b8d720, item=0x8b8d7c0) at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/taskgroup.cpp:136
#13 0xa8f6f6ea in TaskManager::AbstractGroupingStrategy::createGroup (this=0x8a81410, items=...) at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/abstractgroupingstrategy.cpp:118
#14 0xa8f7a12a in TaskManager::ProgramGroupingStrategy::programGrouping (this=0x8a81410, taskItem=0x88f3208, groupItem=0x860cf60)
    at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/strategies/programgroupingstrategy.cpp:180
#15 0xa8f7a47c in TaskManager::ProgramGroupingStrategy::handleItem (this=0x8a81410, item=0x88f3208)
    at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/strategies/programgroupingstrategy.cpp:141
#16 0xa8f73017 in TaskManager::GroupManagerPrivate::addTask (this=0x8633e70, task=...) at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/groupmanager.cpp:278
#17 0xa8f735b5 in TaskManager::GroupManagerPrivate::reloadTasks (this=0x8633e70) at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/groupmanager.cpp:143
#18 0xa8f738d0 in TaskManager::GroupManager::setGroupingStrategy (this=0x845c370, strategy=TaskManager::GroupManager::ProgramGrouping)
    at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/groupmanager.cpp:675
#19 0xa8f739ea in TaskManager::GroupManagerPrivate::checkIfFull (this=0x8633e70) at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/groupmanager.cpp:527
#20 0xa8f1929c in Tasks::adjustGroupingStrategy (this=0x8380740) at /local/svn/kde/trunk/KDE/kdebase/workspace/plasma/applets/tasks/tasks.cpp:241
#21 0xa8f1a057 in Tasks::qt_metacall (this=0x8380740, _c=QMetaObject::InvokeMetaMethod, _id=40, _a=0xbfd0c578) at /local/build/KDE/kdebase/workspace/plasma/applets/tasks/tasks.moc:86
#22 0xb7df9fe4 in QMetaObject::activate (sender=0x8635f30, from_signal_index=14, to_signal_index=14, argv=0xbfd0c578) at /local/git/Qt/qt/src/corelib/kernel/qobject.cpp:3118
#23 0xb7dfab92 in QMetaObject::activate (sender=0x8635f30, m=0xa8f37c24, local_signal_index=1, argv=0xbfd0c578) at /local/git/Qt/qt/src/corelib/kernel/qobject.cpp:3192
#24 0xa8f277c3 in TaskGroupItem::sizeHintChanged (this=0x8635f30, _t1=Qt::PreferredSize) at /local/build/KDE/kdebase/workspace/plasma/applets/tasks/taskgroupitem.moc:136
#25 0xa8f290a8 in TaskGroupItem::updatePreferredSize (this=0x8635f30) at /local/svn/kde/trunk/KDE/kdebase/workspace/plasma/applets/tasks/taskgroupitem.cpp:779
#26 0xa8f1daba in TaskItemLayout::updatePreferredSize (this=0x835ec00) at /local/svn/kde/trunk/KDE/kdebase/workspace/plasma/applets/tasks/taskitemlayout.cpp:400
#27 0xa8f1e926 in TaskItemLayout::layoutItems (this=0x835ec00) at /local/svn/kde/trunk/KDE/kdebase/workspace/plasma/applets/tasks/taskitemlayout.cpp:377
#28 0xa8f1eb52 in TaskItemLayout::insert (this=0x835ec00, index=2, item=0x8adf5e0) at /local/svn/kde/trunk/KDE/kdebase/workspace/plasma/applets/tasks/taskitemlayout.cpp:125
#29 0xa8f1edba in TaskItemLayout::addTaskItem (this=0x835ec00, item=0x8adf5e0) at /local/svn/kde/trunk/KDE/kdebase/workspace/plasma/applets/tasks/taskitemlayout.cpp:82
#30 0xa8f2b0e6 in TaskGroupItem::itemAdded (this=0x8635f30, groupableItem=0x8b808e8) at /local/svn/kde/trunk/KDE/kdebase/workspace/plasma/applets/tasks/taskgroupitem.cpp:448
#31 0xa8f2bc87 in TaskGroupItem::qt_metacall (this=0x8635f30, _c=QMetaObject::InvokeMetaMethod, _id=26, _a=0xbfd0ca48) at /local/build/KDE/kdebase/workspace/plasma/applets/tasks/taskgroupitem.moc:112
#32 0xb7df9fe4 in QMetaObject::activate (sender=0x860cf60, from_signal_index=21, to_signal_index=21, argv=0xbfd0ca48) at /local/git/Qt/qt/src/corelib/kernel/qobject.cpp:3118
#33 0xb7dfab92 in QMetaObject::activate (sender=0x860cf60, m=0xa8fabb54, local_signal_index=0, argv=0xbfd0ca48) at /local/git/Qt/qt/src/corelib/kernel/qobject.cpp:3192
#34 0xa8f8cae3 in TaskManager::TaskGroup::itemAdded (this=0x860cf60, _t1=0x8b808e8) at /local/build/KDE/kdebase/workspace/libs/taskmanager/taskgroup.moc:137
#35 0xa8f8e3e6 in TaskManager::TaskGroup::add (this=0x860cf60, item=0x8b808e8) at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/taskgroup.cpp:136
#36 0xa8f730ca in TaskManager::GroupManagerPrivate::addTask (this=0x8633e70, task=...) at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/groupmanager.cpp:280
#37 0xa8f741a7 in TaskManager::GroupManager::qt_metacall (this=0x845c370, _c=QMetaObject::InvokeMetaMethod, _id=10, _a=0xbfd0cc88)
    at /local/build/KDE/kdebase/workspace/libs/taskmanager/groupmanager.moc:102
#38 0xb7df9fe4 in QMetaObject::activate (sender=0x86060e8, from_signal_index=4, to_signal_index=4, argv=0xbfd0cc88) at /local/git/Qt/qt/src/corelib/kernel/qobject.cpp:3118
#39 0xb7dfab92 in QMetaObject::activate (sender=0x86060e8, m=0xa8fabd1c, local_signal_index=0, argv=0xbfd0cc88) at /local/git/Qt/qt/src/corelib/kernel/qobject.cpp:3192
#40 0xa8f907e3 in TaskManager::TaskManager::taskAdded (this=0x86060e8, _t1=...) at /local/build/KDE/kdebase/workspace/libs/taskmanager/taskmanager.moc:153
#41 0xa8f91a01 in TaskManager::TaskManager::windowAdded (this=0x86060e8, w=52428836) at /local/svn/kde/trunk/KDE/kdebase/workspace/libs/taskmanager/taskmanager.cpp:261
#42 0xa8f91e3f in TaskManager::TaskManager::qt_metacall (this=0x86060e8, _c=QMetaObject::InvokeMetaMethod, _id=6, _a=0xbfd0ce78)
    at /local/build/KDE/kdebase/workspace/libs/taskmanager/taskmanager.moc:108
#43 0xb7df9fe4 in QMetaObject::activate (sender=0x8259d98, from_signal_index=5, to_signal_index=5, argv=0xbfd0ce78) at /local/git/Qt/qt/src/corelib/kernel/qobject.cpp:3118
#44 0xb7dfab92 in QMetaObject::activate (sender=0x8259d98, m=0xb746720c, local_signal_index=1, argv=0xbfd0ce78) at /local/git/Qt/qt/src/corelib/kernel/qobject.cpp:3192
#45 0xb736a603 in KWindowSystem::windowAdded (this=0x8259d98, _t1=52428836) at /local/build/KDE/kdelibs/kdeui/kwindowsystem.moc:121
#46 0xb736cdee in KWindowSystemPrivate::addClient (this=0x819b5c8, w=52428836) at /local/svn/kde/trunk/KDE/kdelibs/kdeui/windowmanagement/kwindowsystem_x11.cpp:229
#47 0xb7379df5 in NETRootInfo::update (this=0x0, dirty_props=0xbfd0d05c) at /local/svn/kde/trunk/KDE/kdelibs/kdeui/windowmanagement/netwm.cpp:2124
#48 0xb737b0ed in NETRootInfo::event (this=0x819b5dc, event=<value optimized out>, properties=0xbfd0d0e0, properties_size=5) at /local/svn/kde/trunk/KDE/kdelibs/kdeui/windowmanagement/netwm.cpp:2053
#49 0xb736d125 in KWindowSystemPrivate::x11Event (this=0x819b5c8, ev=0xbfd0e720) at /local/svn/kde/trunk/KDE/kdelibs/kdeui/windowmanagement/kwindowsystem_x11.cpp:136
#50 0xb723627b in KAppX11HackWidget::publicx11Event (this=0x819b5c8, e=0xbfd0e720) at /local/svn/kde/trunk/KDE/kdelibs/kdeui/kernel/kapplication.cpp:900
#51 0xb7233097 in KApplication::x11EventFilter (this=0x80a0108, _event=0xbfd0e720) at /local/svn/kde/trunk/KDE/kdelibs/kdeui/kernel/kapplication.cpp:950
#52 0xb46343ac in PlasmaApp::x11EventFilter (this=0x80a0108, event=0xbfd0e720) at /local/svn/kde/trunk/KDE/kdebase/workspace/plasma/shells/desktop/plasmaapp.cpp:485
#53 0xb6783900 in qt_x11EventFilter (ev=0xbfd0e720) at /local/git/Qt/qt/src/gui/kernel/qapplication_x11.cpp:381
#54 0xb6794f75 in QApplication::x11ProcessEvent (this=0x80a0108, event=0xbfd0e720) at /local/git/Qt/qt/src/gui/kernel/qapplication_x11.cpp:3339
#55 0xb67c0b32 in x11EventSourceDispatch (s=0x80aafa8, callback=0, user_data=0x0) at /local/git/Qt/qt/src/gui/kernel/qguieventdispatcher_glib.cpp:146
#56 0xb62c09c8 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#57 0xb62c4083 in ?? () from /usr/lib/libglib-2.0.so.0
#58 0xb62c4241 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#59 0xb7e0f2ec in QEventDispatcherGlib::processEvents (this=0x80a6f50, flags=...) at /local/git/Qt/qt/src/corelib/kernel/qeventdispatcher_glib.cpp:327
#60 0xb67c0265 in QGuiEventDispatcherGlib::processEvents (this=0x80a6f50, flags=...) at /local/git/Qt/qt/src/gui/kernel/qguieventdispatcher_glib.cpp:202
#61 0xb7de3659 in QEventLoop::processEvents (this=0xbfd0e9c4, flags=...) at /local/git/Qt/qt/src/corelib/kernel/qeventloop.cpp:149
#62 0xb7de3aaa in QEventLoop::exec (this=0xbfd0e9c4, flags=...) at /local/git/Qt/qt/src/corelib/kernel/qeventloop.cpp:201
#63 0xb7de5f1f in QCoreApplication::exec () at /local/git/Qt/qt/src/corelib/kernel/qcoreapplication.cpp:902
#64 0xb6722427 in QApplication::exec () at /local/git/Qt/qt/src/gui/kernel/qapplication.cpp:3526
#65 0xb461c190 in kdemain (argc=1, argv=0x8088ee0) at /local/svn/kde/trunk/KDE/kdebase/workspace/plasma/shells/desktop/main.cpp:50
#66 0x0804e34f in launch (argc=<value optimized out>, _name=<value optimized out>, args=<value optimized out>, cwd=0x0, envc=0, envs=0x8089437 "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x8051de0 "0") at /local/svn/kde/trunk/KDE/kdelibs/kinit/kinit.cpp:672
#67 0x0804ebdd in handle_launcher_request (sock=7, who=<value optimized out>) at /local/svn/kde/trunk/KDE/kdelibs/kinit/kinit.cpp:1164
#68 0x0804f1fc in handle_requests (waitForPid=<value optimized out>) at /local/svn/kde/trunk/KDE/kdelibs/kinit/kinit.cpp:1357
#69 0x0804fa05 in main (argc=2, argv=0xbfd0f0c4, envp=0xbfd0f0d0) at /local/svn/kde/trunk/KDE/kdelibs/kinit/kinit.cpp:1784

Reported using DrKonqi