Application: plasma-desktop (0.4)
KDE Platform Version: 4.7.3 (4.7.3)
Qt Version: 4.7.4
Operating System: Linux 3.0.0-14-generic x86_64
Distribution: Ubuntu 11.10

-- Information about the crash:
- What I was doing when the application crashed: I was chating in Kopete, Mozilla Firefox was running on Google+ games, VLC, LibreCAD and Dolphin were opened and minimized.
 And then the panel disappeared.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
[Current thread is 1 (Thread 0x7fe69fc217a0 (LWP 1545))]

Thread 4 (Thread 0x7fe67ba9e700 (LWP 1546)):
#0  0x00007fe69f501773 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007fe693a8bf68 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe693a8c429 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe69c6f2f3e in QEventDispatcherGlib::processEvents (this=0x7fe6740008b0, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#4  0x00007fe69c6c6cf2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#5  0x00007fe69c6c6ef7 in QEventLoop::exec (this=0x7fe67ba9ddb0, flags=...) at kernel/qeventloop.cpp:201
#6  0x00007fe69c5de27f in QThread::exec (this=<optimized out>) at thread/qthread.cpp:498
#7  0x00007fe69c6a9cbf in QInotifyFileSystemWatcherEngine::run (this=0x2fd0b40) at io/qfilesystemwatcher_inotify.cpp:248
#8  0x00007fe69c5e0d05 in QThreadPrivate::start (arg=0x2fd0b40) at thread/qthread_unix.cpp:331
#9  0x00007fe694598efc in start_thread (arg=0x7fe67ba9e700) at pthread_create.c:304
#10 0x00007fe69f50d89d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#11 0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7fe67988b700 (LWP 1547)):
#0  0x00007fe69459b040 in __pthread_mutex_lock (mutex=0x3006ff8) at pthread_mutex_lock.c:62
#1  0x00007fe693a8b75f in g_main_context_check () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe693a8bf82 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe693a8c429 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4  0x00007fe69c6f2f3e in QEventDispatcherGlib::processEvents (this=0x3016690, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:424
#5  0x00007fe69c6c6cf2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#6  0x00007fe69c6c6ef7 in QEventLoop::exec (this=0x7fe67988adb0, flags=...) at kernel/qeventloop.cpp:201
#7  0x00007fe69c5de27f in QThread::exec (this=<optimized out>) at thread/qthread.cpp:498
#8  0x00007fe69c6a9cbf in QInotifyFileSystemWatcherEngine::run (this=0x30154e0) at io/qfilesystemwatcher_inotify.cpp:248
#9  0x00007fe69c5e0d05 in QThreadPrivate::start (arg=0x30154e0) at thread/qthread_unix.cpp:331
#10 0x00007fe694598efc in start_thread (arg=0x7fe67988b700) at pthread_create.c:304
#11 0x00007fe69f50d89d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#12 0x0000000000000000 in ?? ()

Thread 2 (Thread 0x7fe66f904700 (LWP 1555)):
#0  0x00007fe69f501773 in __GI___poll (fds=<optimized out>, nfds=<optimized out>, timeout=<optimized out>) at ../sysdeps/unix/sysv/linux/poll.c:87
#1  0x00007fe693a8bf68 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2  0x00007fe693a8c792 in g_main_loop_run () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3  0x00007fe6703e2516 in ?? () from /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#4  0x00007fe693ab12b6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5  0x00007fe694598efc in start_thread (arg=0x7fe66f904700) at pthread_create.c:304
#6  0x00007fe69f50d89d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#7  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fe69fc217a0 (LWP 1545)):
[KCrash Handler]
#6  isNull (this=0x4d0000) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:568
#7  operator! (this=0x4d0000) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:574
#8  TaskManager::TaskItem::task (this=0x4318fe0) at ../../../libs/taskmanager/taskitem.cpp:113
#9  0x00007fe6856f0112 in WindowTaskItem::publishIconGeometry (this=0x3da5e30) at ../../../../../plasma/desktop/applets/tasks/windowtaskitem.cpp:120
#10 0x00007fe6856feb7c in AbstractTaskItem::timerEvent (this=0x3da5e30, event=<optimized out>) at ../../../../../plasma/desktop/applets/tasks/abstracttaskitem.cpp:439
#11 0x00007fe69c6de789 in QObject::event (this=0x3da5e30, e=<optimized out>) at kernel/qobject.cpp:1181
#12 0x00007fe69c09689b in QGraphicsWidget::event (this=0x3da5e30, event=0x7fff60347020) at graphicsview/qgraphicswidget.cpp:1455
#13 0x00007fe69ba78424 in notify_helper (e=0x7fff60347020, receiver=0x3da5e30, this=0x23bf020) at kernel/qapplication.cpp:4486
#14 QApplicationPrivate::notify_helper (this=0x23bf020, receiver=0x3da5e30, e=0x7fff60347020) at kernel/qapplication.cpp:4458
#15 0x00007fe69ba7d291 in QApplication::notify (this=0x23a84c0, receiver=0x3da5e30, e=0x7fff60347020) at kernel/qapplication.cpp:4365
#16 0x00007fe69d376126 in KApplication::notify (this=0x23a84c0, receiver=0x3da5e30, event=0x7fff60347020) at ../../kdeui/kernel/kapplication.cpp:311
#17 0x00007fe69c6c7afc in QCoreApplication::notifyInternal (this=0x23a84c0, receiver=0x3da5e30, event=0x7fff60347020) at kernel/qcoreapplication.cpp:787
#18 0x00007fe69c6f4d62 in sendEvent (event=0x7fff60347020, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#19 QTimerInfoList::activateTimers (this=0x23c5960) at kernel/qeventdispatcher_unix.cpp:603
#20 0x00007fe69c6f2514 in timerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:184
#21 0x00007fe693a8ba5d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#22 0x00007fe693a8c258 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#23 0x00007fe693a8c429 in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#24 0x00007fe69c6f2ed6 in QEventDispatcherGlib::processEvents (this=0x234ef40, flags=<optimized out>) at kernel/qeventdispatcher_glib.cpp:422
#25 0x00007fe69bb2007e in QGuiEventDispatcherGlib::processEvents (this=<optimized out>, flags=<optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#26 0x00007fe69c6c6cf2 in QEventLoop::processEvents (this=<optimized out>, flags=...) at kernel/qeventloop.cpp:149
#27 0x00007fe69c6c6ef7 in QEventLoop::exec (this=0x7fff603472b0, flags=...) at kernel/qeventloop.cpp:201
#28 0x00007fe69c6cb789 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1064
#29 0x00007fe69f80c1a3 in kdemain (argc=1, argv=0x7fff60347698) at ../../../../plasma/desktop/shell/main.cpp:120
#30 0x00007fe69f44d30d in __libc_start_main (main=0x400640 <main(int, char**)>, argc=1, ubp_av=0x7fff60347698, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fff60347688) at libc-start.c:226
#31 0x0000000000400671 in _start ()

Possible duplicates by query: bug 291127, bug 291125, bug 291121, bug 291073, bug 291054.

Reported using DrKonqi