Application: plasma-desktop (0.3)
KDE Version: 4.3.72 (KDE 4.3.72 (KDE 4.4 >= 20091015)) (Compiled from sources)
Qt Version: 4.6.0
Operating System: Linux 2.6.30-1-amd64 x86_64
Distribution: Debian GNU/Linux testing (squeeze)

What I was doing when the application crashed:
Sometimes I get this crash I have no idea what is causing it. Plasma desktop is crashing about 4-6 times per day (8 hours). 

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 1 (Thread 0x7fa9293b87f0 (LWP 3836))]

Thread 2 (Thread 0x7fa901cf4910 (LWP 3837)):
#0  0x00007fa928c4af99 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#1  0x00007fa928ee4979 in QWaitConditionPrivate::wait (this=0x2dd7340, mutex=0x2dd7338, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:87
#2  QWaitCondition::wait (this=0x2dd7340, mutex=0x2dd7338, time=18446744073709551615) at thread/qwaitcondition_unix.cpp:159
#3  0x00007fa927ac2c74 in QHostInfoAgent::run (this=0x2dd7320) at kernel/qhostinfo.cpp:252
#4  0x00007fa928ee3a85 in QThreadPrivate::start (arg=0x2dd7320) at thread/qthread_unix.cpp:244
#5  0x00007fa928c4673a in start_thread () from /lib/libpthread.so.0
#6  0x00007fa9255e749d in clone () from /lib/libc.so.6
#7  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fa9293b87f0 (LWP 3836)):
[KCrash Handler]
#5  QGraphicsScenePrivate::processDirtyItemsRecursive (this=0x2590910, item=0x3623bf0, dirtyAncestorContainsChildren=false, parentOpacity=-nan(0xfffffffffff00))
    at graphicsview/qgraphicsscene.cpp:4798
#6  0x00007fa92681e397 in QGraphicsScenePrivate::_q_processDirtyItems (this=0x2590910) at graphicsview/qgraphicsscene.cpp:455
#7  0x00007fa92681e90a in QGraphicsScene::qt_metacall (this=0x2595f20, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x3630ed0) at .moc/release-shared/moc_qgraphicsscene.cpp:128
#8  0x00007fa91a1f94a5 in Plasma::Corona::qt_metacall(QMetaObject::Call, int, void**) () from /opt/kde4/lib/libplasma.so.3
#9  0x00007fa915ab1625 in DesktopCorona::qt_metacall(QMetaObject::Call, int, void**) () from /opt/kde4/lib/libkdeinit4_plasma-desktop.so
#10 0x00007fa928fe7728 in QObject::event (this=0x2595f20, e=0x345fec0) at kernel/qobject.cpp:1238
#11 0x00007fa9268197a2 in QGraphicsScene::event (this=0x2595f20, event=0x345fec0) at graphicsview/qgraphicsscene.cpp:3366
#12 0x00007fa92620acad in QApplicationPrivate::notify_helper (this=0x2474a20, receiver=0x2595f20, e=0x345fec0) at kernel/qapplication.cpp:4277
#13 0x00007fa926212159 in QApplication::notify (this=0x245d230, receiver=0x2595f20, e=0x345fec0) at kernel/qapplication.cpp:4166
#14 0x00007fa9273dd76b in KApplication::notify(QObject*, QEvent*) () from /opt/kde4/lib/libkdeui.so.5
#15 0x00007fa928fd765c in QCoreApplication::notifyInternal (this=0x245d230, receiver=0x2595f20, event=0x345fec0) at kernel/qcoreapplication.cpp:704
#16 0x00007fa928fd853c in QCoreApplication::sendEvent (receiver=0x0, event_type=0, data=0x23ea5d0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#17 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x23ea5d0) at kernel/qcoreapplication.cpp:1345
#18 0x00007fa929001423 in QCoreApplication::sendPostedEvents (s=<value optimized out>) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#19 postEventSourceDispatch (s=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:276
#20 0x00007fa924a6b12a in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#21 0x00007fa924a6e988 in ?? () from /lib/libglib-2.0.so.0
#22 0x00007fa924a6eb3c in g_main_context_iteration () from /lib/libglib-2.0.so.0
#23 0x00007fa929000f8c in QEventDispatcherGlib::processEvents (this=0x24744b0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:407
#24 0x00007fa9262b141f in QGuiEventDispatcherGlib::processEvents (this=0x2590910, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#25 0x00007fa928fd5f62 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#26 0x00007fa928fd6334 in QEventLoop::exec (this=0x7ffff848d0d0, flags=...) at kernel/qeventloop.cpp:201
#27 0x00007fa928fd87c6 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:981
#28 0x00007fa915ab8a7c in kdemain () from /opt/kde4/lib/libkdeinit4_plasma-desktop.so
#29 0x00000000004074b4 in launch(int, char const*, char const*, char const*, int, char const*, bool, char const*, bool, char const*) ()
#30 0x0000000000407c78 in handle_launcher_request(int, char const*) ()
#31 0x0000000000408111 in handle_requests(int) ()
#32 0x00000000004088cb in main ()

Reported using DrKonqi