Application that crashed: plasma-desktop
Version of the application: 0.3
KDE Version: 4.3.1 (KDE 4.3.1)
Qt Version: 4.5.2
Operating System: Linux 2.6.28-15-generic i686
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
Plasmoid for system monitor is added to the panel successfully. After attempting remove any of the monitors via the settings, the plasma desktop crashes and restarts. This is freely reproducible.

 -- Backtrace:
Application: Plasma Workspace (kdeinit4), signal: Segmentation fault
[Current thread is 0 (LWP 14839)]

Thread 2 (Thread 0xa86dab90 (LWP 14842)):
#0  0xb80dc430 in __kernel_vsyscall ()
#1  0xb65f70e5 in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/tls/i686/cmov/libpthread.so.0
#2  0xb67d72ed in pthread_cond_wait () from /lib/tls/i686/cmov/libc.so.6
#3  0xb7edc172 in QWaitCondition::wait (this=0x9f0a1e8, mutex=0x9f0a1e4, time=4294967295) at thread/qwaitcondition_unix.cpp:87
#4  0xb781aac2 in QHostInfoAgent::run (this=0x9f0a1d8) at kernel/qhostinfo.cpp:260
#5  0xb7edb132 in QThreadPrivate::start (arg=0x9f0a1d8) at thread/qthread_unix.cpp:188
#6  0xb65f34ff in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#7  0xb67c849e in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb60ff700 (LWP 14839)):
[KCrash Handler]
#6  Plasma::Containment::containmentType (this=0xb04a388) at /build/buildd/kde4libs-4.3.1/plasma/containment.cpp:417
#7  0xa7231323 in SystemMonitor::removeApplet (this=0xaea19e8, name=@0xbfdf4bc8) at /build/buildd/kdebase-workspace-4.3.1/plasma/applets/system-monitor/system-monitor.cpp:156
#8  0xa723294a in SystemMonitor::toggled (this=0xaea19e8, toggled=false) at /build/buildd/kdebase-workspace-4.3.1/plasma/applets/system-monitor/system-monitor.cpp:108
#9  0xa7232a85 in SystemMonitor::qt_metacall (this=0xaea19e8, _c=QMetaObject::InvokeMetaMethod, _id=1, _a=0xbfdf4ccc)
    at /build/buildd/kdebase-workspace-4.3.1/obj-i486-linux-gnu/plasma/applets/system-monitor/system-monitor.moc:72
#10 0xb7fe51b8 in QMetaObject::activate (sender=0xaf75808, from_signal_index=8, to_signal_index=8, argv=0xbfdf4ccc) at kernel/qobject.cpp:3113
#11 0xb7fe5e42 in QMetaObject::activate (sender=0xaf75808, m=0xb5fd05dc, local_signal_index=1, argv=0xbfdf4ccc) at kernel/qobject.cpp:3187
#12 0xb5f12f19 in Plasma::PushButton::toggled (this=0xaf75808, _t1=false) at /build/buildd/kde4libs-4.3.1/obj-i486-linux-gnu/plasma/pushbutton.moc:140
#13 0xb5f14780 in Plasma::PushButton::qt_metacall (this=0xaf75808, _c=QMetaObject::InvokeMetaMethod, _id=1, _a=0xbfdf4e1c) at /build/buildd/kde4libs-4.3.1/obj-i486-linux-gnu/plasma/pushbutton.moc:85
#14 0xa7233c5a in MonitorButton::qt_metacall (this=0xaf75808, _c=QMetaObject::InvokeMetaMethod, _id=8, _a=0xbfdf4e1c)
    at /build/buildd/kdebase-workspace-4.3.1/obj-i486-linux-gnu/plasma/applets/system-monitor/monitorbutton.moc:67
#15 0xb7fe51b8 in QMetaObject::activate (sender=0xaf74b30, from_signal_index=31, to_signal_index=31, argv=0xbfdf4e1c) at kernel/qobject.cpp:3113
#16 0xb7fe5e42 in QMetaObject::activate (sender=0xaf74b30, m=0xb73080a4, local_signal_index=4, argv=0xbfdf4e1c) at kernel/qobject.cpp:3187
#17 0xb711eeb9 in QAbstractButton::toggled (this=0xaf74b30, _t1=false) at .moc/release-shared/moc_qabstractbutton.cpp:207
#18 0xb6e48385 in QAbstractButton::setChecked (this=0xaf74b30, checked=false) at widgets/qabstractbutton.cpp:763
#19 0xb6e48560 in QAbstractButton::nextCheckState (this=0xaf74b30) at widgets/qabstractbutton.cpp:1017
#20 0xb6e48003 in QAbstractButtonPrivate::click (this=0x98fddc8) at widgets/qabstractbutton.cpp:525
#21 0xb6e482d6 in QAbstractButton::mouseReleaseEvent (this=0xaf74b30, e=0xafc36a8) at widgets/qabstractbutton.cpp:1115
#22 0xb6ae4973 in QWidget::event (this=0xaf74b30, event=0xafc36a8) at kernel/qwidget.cpp:7549
#23 0xb6e4628e in QAbstractButton::event (this=0xaf74b30, e=0xafc36a8) at widgets/qabstractbutton.cpp:1077
#24 0xb6ef1050 in QPushButton::event (this=0xaf74b30, e=0xafc36a8) at widgets/qpushbutton.cpp:662
#25 0xb6a8dd3c in QApplicationPrivate::notify_helper (this=0x98da3a8, receiver=0xaf74b30, e=0xafc36a8) at kernel/qapplication.cpp:4056
#26 0xb6a969b1 in QApplication::notify (this=0x989c4c8, receiver=0xaf74b30, e=0xafc36a8) at kernel/qapplication.cpp:3758
#27 0xb759d85d in KApplication::notify (this=0x989c4c8, receiver=0xaf74b30, event=0xafc36a8) at /build/buildd/kde4libs-4.3.1/kdeui/kernel/kapplication.cpp:302
#28 0xb7fcfbcb in QCoreApplication::notifyInternal (this=0x989c4c8, receiver=0xaf74b30, event=0xafc36a8) at kernel/qcoreapplication.cpp:610
#29 0xb6a95a1e in QApplicationPrivate::sendMouseEvent (receiver=0xaf74b30, event=0xafc36a8, alienWidget=0x0, nativeWidget=0xaf74b30, buttonDown=0xbfdf543c, lastMouseReceiver=@0xaf089e4)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#30 0xb70ffb51 in QGraphicsProxyWidgetPrivate::sendWidgetMouseEvent (this=0xaf08888, event=0xbfdf5a54) at graphicsview/qgraphicsproxywidget.cpp:278
#31 0xb709b144 in QGraphicsItem::sceneEvent (this=0xaf75810, event=0xbfdf5a54) at graphicsview/qgraphicsitem.cpp:5030
#32 0xb70eb95f in QGraphicsWidget::sceneEvent (this=0xaf75808, event=0xbfdf5a54) at graphicsview/qgraphicswidget.cpp:1110
#33 0xb70c07bc in QGraphicsScenePrivate::sendEvent (this=0x9989e58, item=0xaf75810, event=0xbfdf5a54) at graphicsview/qgraphicsscene.cpp:1159
#34 0xb70c1e22 in QGraphicsScenePrivate::sendMouseEvent (this=0x9989e58, mouseEvent=0xbfdf5a54) at graphicsview/qgraphicsscene.cpp:1230
#35 0xb70cc431 in QGraphicsScene::mouseReleaseEvent (this=0x98da188, mouseEvent=0xbfdf5a54) at graphicsview/qgraphicsscene.cpp:4445
#36 0xb70ce08a in QGraphicsScene::event (this=0x98da188, event=0xbfdf5a54) at graphicsview/qgraphicsscene.cpp:3808
#37 0xb6a8dd3c in QApplicationPrivate::notify_helper (this=0x98da3a8, receiver=0x98da188, e=0xbfdf5a54) at kernel/qapplication.cpp:4056
#38 0xb6a9603e in QApplication::notify (this=0x989c4c8, receiver=0x98da188, e=0xbfdf5a54) at kernel/qapplication.cpp:3603
#39 0xb759d85d in KApplication::notify (this=0x989c4c8, receiver=0x98da188, event=0xbfdf5a54) at /build/buildd/kde4libs-4.3.1/kdeui/kernel/kapplication.cpp:302
#40 0xb7fcfbcb in QCoreApplication::notifyInternal (this=0x989c4c8, receiver=0x98da188, event=0xbfdf5a54) at kernel/qcoreapplication.cpp:610
#41 0xb70e0712 in QGraphicsView::mouseReleaseEvent (this=0xacd9f78, event=0xbfdf6058) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#42 0xb6ae4973 in QWidget::event (this=0xacd9f78, event=0xbfdf6058) at kernel/qwidget.cpp:7549
#43 0xb6e95a53 in QFrame::event (this=0xacd9f78, e=0xbfdf6058) at widgets/qframe.cpp:559
#44 0xb6f35c2f in QAbstractScrollArea::viewportEvent (this=0xacd9f78, e=0x0) at widgets/qabstractscrollarea.cpp:962
#45 0xb70e09b2 in QGraphicsView::viewportEvent (this=0xacd9f78, event=0xbfdf6058) at graphicsview/qgraphicsview.cpp:2919
#46 0xb6f38235 in QAbstractScrollAreaFilter::eventFilter (this=0xafac7f0, o=0x990ad68, e=0xbfdf6058) at widgets/qabstractscrollarea_p.h:100
#47 0xb7fcedea in QCoreApplicationPrivate::sendThroughObjectEventFilters (this=0x98da3a8, receiver=0x990ad68, event=0xbfdf6058) at kernel/qcoreapplication.cpp:726
#48 0xb6a8dd1a in QApplicationPrivate::notify_helper (this=0x98da3a8, receiver=0x990ad68, e=0xbfdf6058) at kernel/qapplication.cpp:4052
#49 0xb6a969b1 in QApplication::notify (this=0x989c4c8, receiver=0x990ad68, e=0xbfdf6058) at kernel/qapplication.cpp:3758
#50 0xb759d85d in KApplication::notify (this=0x989c4c8, receiver=0x990ad68, event=0xbfdf6058) at /build/buildd/kde4libs-4.3.1/kdeui/kernel/kapplication.cpp:302
#51 0xb7fcfbcb in QCoreApplication::notifyInternal (this=0x989c4c8, receiver=0x990ad68, event=0xbfdf6058) at kernel/qcoreapplication.cpp:610
#52 0xb6a95a1e in QApplicationPrivate::sendMouseEvent (receiver=0x990ad68, event=0xbfdf6058, alienWidget=0x990ad68, nativeWidget=0xae10510, buttonDown=0xb730faa0, lastMouseReceiver=@0xb730faa4)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#53 0xb6b05cce in QETWidget::translateMouseEvent (this=0xae10510, event=0xbfdf76ec) at kernel/qapplication_x11.cpp:4409
#54 0xb6b05085 in QApplication::x11ProcessEvent (this=0x989c4c8, event=0xbfdf76ec) at kernel/qapplication_x11.cpp:3428
#55 0xb6b3037a in x11EventSourceDispatch (s=0x98dcbb0, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#56 0xb663fb88 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#57 0xb66430eb in ?? () from /usr/lib/libglib-2.0.so.0
#58 0xb6643268 in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#59 0xb7ffb2f8 in QEventDispatcherGlib::processEvents (this=0x98da198, flags={i = -1075873624}) at kernel/qeventdispatcher_glib.cpp:327
#60 0xb6b2fa75 in QGuiEventDispatcherGlib::processEvents (this=0x98da198, flags={i = -1075873576}) at kernel/qguieventdispatcher_glib.cpp:202
#61 0xb7fce1fa in QEventLoop::processEvents (this=0xbfdf7950, flags={i = -1075873512}) at kernel/qeventloop.cpp:149
#62 0xb7fce642 in QEventLoop::exec (this=0xbfdf7950, flags={i = -1075873448}) at kernel/qeventloop.cpp:201
#63 0xb7fd0ae9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#64 0xb6a8dbb7 in QApplication::exec () at kernel/qapplication.cpp:3525
#65 0xb3e7d310 in kdemain (argc=1, argv=0x98624c8) at /build/buildd/kdebase-workspace-4.3.1/plasma/shells/desktop/main.cpp:50
#66 0x0804e27d in launch (argc=1, _name=0x986357c "/usr/bin/plasma-desktop", args=0x9863594 "", cwd=0x0, envc=0, envs=0x9863598 "", reset_env=false, tty=0x0, avoid_loops=false, 
    startup_id_str=0x805136d "0") at /build/buildd/kde4libs-4.3.1/kinit/kinit.cpp:677
#67 0x0804ea5d in handle_launcher_request (sock=7, who=<value optimized out>) at /build/buildd/kde4libs-4.3.1/kinit/kinit.cpp:1169
#68 0x0804efe5 in handle_requests (waitForPid=0) at /build/buildd/kde4libs-4.3.1/kinit/kinit.cpp:1362
#69 0x0804fbca in main (argc=2, argv=0xbfdf8144, envp=0xbfdf8150) at /build/buildd/kde4libs-4.3.1/kinit/kinit.cpp:1793

This bug may be a duplicate of or related to bug 207575

Reported using DrKonqi