Application: plasma-desktop (0.4)
KDE Platform Version: 4.7.3 (4.7.3)
Qt Version: 4.7.4
Operating System: Linux 3.0.0-15-generic i686
Distribution: Ubuntu 11.10

-- Information about the crash:
- What I was doing when the application crashed:
Switching tabs in a browser, opening a minimized window, etc.
- Unusual behavior I noticed:
Plasma crashes - sometimes it will restart on its own, other times i`m just dead and have to control alt delete and logout, then in. Or reboot. 

This is my first bug report in 5 years so please bear with me if i`m doing anything unusual!

The crash can be reproduced some of the time.

-- Backtrace:
Application: Plasma Desktop Shell (plasma-desktop), signal: Segmentation fault
[Current thread is 1 (Thread 0xb774cb20 (LWP 6193))]

Thread 3 (Thread 0xb17dbb70 (LWP 6194)):
#0  0x0258bd44 in __pthread_mutex_unlock_usercnt () from /lib/i386-linux-gnu/libpthread.so.0
#1  0x0083cf54 in pthread_mutex_unlock () from /lib/i386-linux-gnu/libc.so.6
#2  0x02345785 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#3  0x02345c2a in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#4  0x034ceb37 in QEventDispatcherGlib::processEvents (this=0x8906038, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#5  0x0349f1dd in QEventLoop::processEvents (this=0xb17db2a0, flags=...) at kernel/qeventloop.cpp:149
#6  0x0349f421 in QEventLoop::exec (this=0xb17db2a0, flags=...) at kernel/qeventloop.cpp:201
#7  0x033a290b in QThread::exec (this=0x8903b48) at thread/qthread.cpp:498
#8  0x0347fe2d in QInotifyFileSystemWatcherEngine::run (this=0x8903b48) at io/qfilesystemwatcher_inotify.cpp:248
#9  0x033a57b3 in QThreadPrivate::start (arg=0x8903b48) at thread/qthread_unix.cpp:331
#10 0x02588d31 in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#11 0x0082f0ce in clone () from /lib/i386-linux-gnu/libc.so.6
Backtrace stopped: Not enough registers or memory available to unwind further

Thread 2 (Thread 0xafe91b70 (LWP 6195)):
#0  0x0258bd44 in __pthread_mutex_unlock_usercnt () from /lib/i386-linux-gnu/libpthread.so.0
#1  0x0083cf54 in pthread_mutex_unlock () from /lib/i386-linux-gnu/libc.so.6
#2  0x0234487f in g_main_context_prepare () from /lib/i386-linux-gnu/libglib-2.0.so.0
#3  0x02345637 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#4  0x02345c2a in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#5  0x034ceb37 in QEventDispatcherGlib::processEvents (this=0x8a2fca0, flags=...) at kernel/qeventdispatcher_glib.cpp:424
#6  0x0349f1dd in QEventLoop::processEvents (this=0xafe912a0, flags=...) at kernel/qeventloop.cpp:149
#7  0x0349f421 in QEventLoop::exec (this=0xafe912a0, flags=...) at kernel/qeventloop.cpp:201
#8  0x033a290b in QThread::exec (this=0x860c9f8) at thread/qthread.cpp:498
#9  0x0347fe2d in QInotifyFileSystemWatcherEngine::run (this=0x860c9f8) at io/qfilesystemwatcher_inotify.cpp:248
#10 0x033a57b3 in QThreadPrivate::start (arg=0x860c9f8) at thread/qthread_unix.cpp:331
#11 0x02588d31 in start_thread () from /lib/i386-linux-gnu/libpthread.so.0
#12 0x0082f0ce in clone () from /lib/i386-linux-gnu/libc.so.6
Backtrace stopped: Not enough registers or memory available to unwind further

Thread 1 (Thread 0xb774cb20 (LWP 6193)):
[KCrash Handler]
#7  isNull (this=0x1) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:568
#8  operator! (this=0x1) at /usr/include/qt4/QtCore/qsharedpointer_impl.h:574
#9  TaskManager::TaskItem::task (this=0x92909a8) at ../../../libs/taskmanager/taskitem.cpp:113
#10 0x03301662 in WindowTaskItem::publishIconGeometry (this=0x912bba8) at ../../../../../plasma/desktop/applets/tasks/windowtaskitem.cpp:120
#11 0x03312688 in AbstractTaskItem::timerEvent (this=0x912bba8, event=0xbfbe1a1c) at ../../../../../plasma/desktop/applets/tasks/abstracttaskitem.cpp:439
#12 0x034b8994 in QObject::event (this=0x912bba8, e=0xbfbe1a1c) at kernel/qobject.cpp:1181
#13 0x07930bd4 in QGraphicsWidget::event (this=0x912bba8, event=0xbfbe1a1c) at graphicsview/qgraphicswidget.cpp:1455
#14 0x07271d54 in notify_helper (e=0xbfbe1a1c, receiver=0x912bba8, this=0x8234520) at kernel/qapplication.cpp:4486
#15 QApplicationPrivate::notify_helper (this=0x8234520, receiver=0x912bba8, e=0xbfbe1a1c) at kernel/qapplication.cpp:4458
#16 0x07277103 in QApplication::notify (this=0xbfbe1a1c, receiver=0x912bba8, e=0xbfbe1a1c) at kernel/qapplication.cpp:3886
#17 0x01165681 in KApplication::notify (this=0x8225358, receiver=0x912bba8, event=0xbfbe1a1c) at ../../kdeui/kernel/kapplication.cpp:311
#18 0x034a019e in QCoreApplication::notifyInternal (this=0x8225358, receiver=0x912bba8, event=0xbfbe1a1c) at kernel/qcoreapplication.cpp:787
#19 0x034d0c10 in sendEvent (event=0xbfbe1a1c, receiver=<optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#20 QTimerInfoList::activateTimers (this=0x8239134) at kernel/qeventdispatcher_unix.cpp:603
#21 0x034ce155 in timerSourceDispatch (source=<optimized out>) at kernel/qeventdispatcher_glib.cpp:184
#22 idleTimerSourceDispatch (source=0x8239168) at kernel/qeventdispatcher_glib.cpp:231
#23 0x0234525f in g_main_context_dispatch () from /lib/i386-linux-gnu/libglib-2.0.so.0
#24 0x02345990 in ?? () from /lib/i386-linux-gnu/libglib-2.0.so.0
#25 0x02345c2a in g_main_context_iteration () from /lib/i386-linux-gnu/libglib-2.0.so.0
#26 0x034ceada in QEventDispatcherGlib::processEvents (this=0x81eb218, flags=...) at kernel/qeventdispatcher_glib.cpp:422
#27 0x07329e3a in QGuiEventDispatcherGlib::processEvents (this=0x81eb218, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#28 0x0349f1dd in QEventLoop::processEvents (this=0xbfbe1c94, flags=...) at kernel/qeventloop.cpp:149
#29 0x0349f421 in QEventLoop::exec (this=0xbfbe1c94, flags=...) at kernel/qeventloop.cpp:201
#30 0x034a419d in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1064
#31 0x0726f8f4 in QApplication::exec () at kernel/qapplication.cpp:3760
#32 0x0041118b in kdemain (argc=1, argv=0xbfbe1e94) at ../../../../plasma/desktop/shell/main.cpp:120
#33 0x0804850b in main (argc=1, argv=0xbfbe1e94) at plasma-desktop_dummy.cpp:3

Possible duplicates by query: bug 290635, bug 290597, bug 290581, bug 290561, bug 290559.

Reported using DrKonqi