Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.4 (KDE 4.3.4)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-15-generic x86_64
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
Removed Fancy Tasks widget from main panel after testing (right clicked on main panel, chose "Remove Fancy Tasks" option which lead to Plasma workspace crash.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
The current source language is "auto; currently c".
[Current thread is 1 (Thread 0x7f8c85016750 (LWP 3424))]

Thread 3 (Thread 0x7f8c60043910 (LWP 3427)):
#0  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:261
#1  0x00007f8c84a644fb in QWaitConditionPrivate::wait (this=<value optimized out>, mutex=0x2534138, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:87
#2  QWaitCondition::wait (this=<value optimized out>, mutex=0x2534138, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:159
#3  0x00007f8c80e9778c in QHostInfoAgent::run (this=0x2534120) at kernel/qhostinfo.cpp:260
#4  0x00007f8c84a63445 in QThreadPrivate::start (arg=0x2534120) at thread/qthread_unix.cpp:188
#5  0x00007f8c817d5a04 in start_thread (arg=<value optimized out>) at pthread_create.c:300
#6  0x00007f8c823b57bd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#7  0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7f8c5e7b7910 (LWP 3428)):
#0  __lll_lock_wait_private () at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:97
#1  0x00007f8c82352a93 in _L_lock_9264 () from /lib/libc.so.6
#2  0x00007f8c82350701 in *__GI___libc_free (mem=0x7f8c82640e40) at malloc.c:3714
#3  0x00007f8c81a264f3 in ?? () from /lib/libglib-2.0.so.0
#4  0x00007f8c84b72ce2 in ~QEventDispatcherGlib (this=0x2869080, __in_chrg=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:289
#5  0x00007f8c84a635fc in QThreadPrivate::finish (arg=<value optimized out>) at thread/qthread_unix.cpp:212
#6  0x00007f8c84a6344d in ~__pthread_cleanup_class (arg=0x1c08970) at /usr/include/pthread.h:535
#7  QThreadPrivate::start (arg=0x1c08970) at thread/qthread_unix.cpp:190
#8  0x00007f8c817d5a04 in start_thread (arg=<value optimized out>) at pthread_create.c:300
#9  0x00007f8c823b57bd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#10 0x0000000000000000 in ?? ()
The current source language is "auto; currently asm".

Thread 1 (Thread 0x7f8c85016750 (LWP 3424)):
[KCrash Handler]
#5  malloc_consolidate (av=0x7f8c82640e40) at malloc.c:5089
#6  0x00007f8c8234e4c9 in _int_malloc (av=0x7f8c82640e40, bytes=257) at malloc.c:4338
#7  0x00007f8c823510c6 in _int_realloc (av=0x7f8c82640e40, oldp=0x4783de0, oldsize=<value optimized out>, nb=<value optimized out>) at malloc.c:5224
#8  0x00007f8c823515b0 in *__GI___libc_realloc (oldmem=0x4783df0, bytes=1024) at malloc.c:3799
#9  0x00007f8c84a870db in QListData::realloc (this=0x7fffc0f06e40, alloc=-2107371968) at tools/qlistdata.cpp:111
#10 0x00007f8c84a8730d in QListData::append (this=0x7fffc0f06e40) at tools/qlistdata.cpp:131
#11 0x00007f8c830aeedf in QList<QGraphicsItem*>::append (this=0x7fffc0f06e40, t=@0x101) at ../../include/QtCore/../../src/corelib/tools/qlist.h:429
#12 0x00007f8c830a62e7 in QList<QGraphicsItem*>::operator<< (this=0x1cf3470, rect=<value optimized out>) at ../../include/QtCore/../../src/corelib/tools/qlist.h:304
#13 QGraphicsScenePrivate::estimateItemsInRect (this=0x1cf3470, rect=<value optimized out>) at graphicsview/qgraphicsscene.cpp:422
#14 0x00007f8c830a6875 in QGraphicsScenePrivate::items_helper (this=<value optimized out>, path=..., mode=Qt::IntersectsItemBoundingRect, order=<value optimized out>)
    at graphicsview/qgraphicsscene.cpp:1548
#15 0x00007f8c830bca69 in QGraphicsViewPrivate::findItems (this=0x2bb9660, exposedRegion=<value optimized out>, allItems=<value optimized out>) at graphicsview/qgraphicsview.cpp:1113
#16 0x00007f8c830bf940 in QGraphicsView::paintEvent (this=0x2d845e0, event=<value optimized out>) at graphicsview/qgraphicsview.cpp:3470
#17 0x00007f8c82b447a0 in QWidget::event (this=0x2d845e0, event=0x7fffc0f07c60) at kernel/qwidget.cpp:7687
#18 0x00007f8c82ea02a6 in QFrame::event (this=0x2d845e0, e=0x7fffc0f07c60) at widgets/qframe.cpp:559
#19 0x00007f8c830bd92b in QGraphicsView::viewportEvent (this=0x2d845e0, event=0x7fffc0f07c60) at graphicsview/qgraphicsview.cpp:2919
#20 0x00007f8c84b48f47 in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=<value optimized out>, receiver=0x2bbb040, event=0x7fffc0f07c60) at kernel/qcoreapplication.cpp:726
#21 0x00007f8c82af5ecc in QApplicationPrivate::notify_helper (this=0x1c045c0, receiver=0x2bbb040, e=0x7fffc0f07c60) at kernel/qapplication.cpp:4052
#22 0x00007f8c82afd1ce in QApplication::notify (this=0x1bfb460, receiver=0x2bbb040, e=0x7fffc0f07c60) at kernel/qapplication.cpp:4021
#23 0x00007f8c8372ce56 in KApplication::notify (this=0x1bfb460, receiver=0x2bbb040, event=0x7fffc0f07c60) at ../../kdeui/kernel/kapplication.cpp:302
#24 0x00007f8c84b49c2c in QCoreApplication::notifyInternal (this=0x1bfb460, receiver=0x2bbb040, event=0x7fffc0f07c60) at kernel/qcoreapplication.cpp:610
#25 0x00007f8c82b4bb93 in QCoreApplication::sendSpontaneousEvent (this=0x2bbb070, pdev=0x2bbc158, rgn=..., offset=<value optimized out>, flags=<value optimized out>, 
    sharedPainter=<value optimized out>, backingStore=0x2bbc0f0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#26 QWidgetPrivate::drawWidget (this=0x2bbb070, pdev=0x2bbc158, rgn=..., offset=<value optimized out>, flags=<value optimized out>, sharedPainter=<value optimized out>, backingStore=0x2bbc0f0)
    at kernel/qwidget.cpp:5079
#27 0x00007f8c82cbddbe in QWidgetBackingStore::sync (this=0x2bbc0f0) at painting/qbackingstore.cpp:1261
#28 0x00007f8c82b3dfa0 in QWidgetPrivate::syncBackingStore (this=0x2bb9660) at kernel/qwidget.cpp:1603
#29 0x00007f8c82b445b8 in QWidget::event (this=0x2d845e0, event=0x4746b60) at kernel/qwidget.cpp:7827
#30 0x00007f8c82ea02a6 in QFrame::event (this=0x2d845e0, e=0x4746b60) at widgets/qframe.cpp:559
#31 0x00007f8c82f2fbc9 in QAbstractScrollArea::event (this=0x2d845e0, e=0x4746b60) at widgets/qabstractscrollarea.cpp:918
#32 0x00007f8c82af5efc in QApplicationPrivate::notify_helper (this=0x1c045c0, receiver=0x2d845e0, e=0x4746b60) at kernel/qapplication.cpp:4056
#33 0x00007f8c82afd1ce in QApplication::notify (this=0x1bfb460, receiver=0x2d845e0, e=0x4746b60) at kernel/qapplication.cpp:4021
#34 0x00007f8c8372ce56 in KApplication::notify (this=0x1bfb460, receiver=0x2d845e0, event=0x4746b60) at ../../kdeui/kernel/kapplication.cpp:302
#35 0x00007f8c84b49c2c in QCoreApplication::notifyInternal (this=0x1bfb460, receiver=0x2d845e0, event=0x4746b60) at kernel/qcoreapplication.cpp:610
#36 0x00007f8c84b4a80a in QCoreApplication::sendEvent (receiver=0x0, event_type=<value optimized out>, data=0x1b6e4d0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#37 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=<value optimized out>, data=0x1b6e4d0) at kernel/qcoreapplication.cpp:1247
#38 0x00007f8c84b72533 in QCoreApplication::sendPostedEvents (s=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:218
#39 postEventSourceDispatch (s=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:210
#40 0x00007f8c81a26bce in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#41 0x00007f8c81a2a598 in ?? () from /lib/libglib-2.0.so.0
#42 0x00007f8c81a2a6c0 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#43 0x00007f8c84b721a6 in QEventDispatcherGlib::processEvents (this=0x1b71040, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:327
#44 0x00007f8c82b8a4be in QGuiEventDispatcherGlib::processEvents (this=0x47c75b0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#45 0x00007f8c84b48532 in QEventLoop::processEvents (this=<value optimized out>, flags=) at kernel/qeventloop.cpp:149
#46 0x00007f8c84b48904 in QEventLoop::exec (this=0x7fffc0f08ad0, flags=) at kernel/qeventloop.cpp:201
#47 0x00007f8c84b4aab9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#48 0x00007f8c78d704cf in kdemain (argc=<value optimized out>, argv=<value optimized out>) at ../../../../plasma/shells/desktop/main.cpp:50
#49 0x0000000000406da8 in launch (argc=1, _name=<value optimized out>, args=<value optimized out>, cwd=<value optimized out>, envc=0, envs=<value optimized out>, reset_env=false, tty=0x0, 
    avoid_loops=false, startup_id_str=0x40a299 "0") at ../../kinit/kinit.cpp:677
#50 0x0000000000407aa0 in handle_launcher_request (sock=8, who=<value optimized out>) at ../../kinit/kinit.cpp:1169
#51 0x0000000000407f51 in handle_requests (waitForPid=0) at ../../kinit/kinit.cpp:1362
#52 0x0000000000408bb2 in main (argc=2, argv=<value optimized out>, envp=<value optimized out>) at ../../kinit/kinit.cpp:1793
The current source language is "auto; currently c".

Reported using DrKonqi