Application: systemsettings (1.0)
KDE Platform Version: 4.4.1 (KDE 4.4.1)
Qt Version: 4.6.2
Operating System: Linux 2.6.31-10-rt i686
Distribution: Ubuntu lucid (development branch)

-- Information about the crash:
** Bug Description **
I'm not sure yet if I'll be able to reproduce this if I restart, but here's what happened:
1) I installed the traybiff package using "Add and Remove Software" from the KDE system settings.
2) After installing, the add/remove window still showed the package as marked for installation (not installed), and the "Apply" button could still be pressed.  I pressed "Apply" and then the package manager let me know that the package couldn't be installed because it was already installed.  After I closed out of that window, the package manager crashed.
3) After I realized that traybiff doesn't install into Thunderbird 3, I proceeded to uninstall it, and ran into the same problem (package still showing as marked for removal after it was already removed).  I clicked "Apply" again to remove the package, got the message that the package was already not installed, and then the crash.

** My System **
Motherboard: MSI K9N SLI Platinum (nForce 570 SLI chipset)
CPU: AMD Athlon(tm) 64 Processor 4000+ (2.6 GHz)
RAM: 2GB DDR2
Video: Dell NVIDIA GeForce 7800 GTX w/ 256 MB RAM (PCI Express)
OS: Kubuntu 10.04 i386 beta 1
Linux Kernel: 2.6.31-10-rt
NVIDIA driver: 195.36.15-0ubuntu1
Screen Resolution: 1280 x 960
X.org: 1:7.5+3ubuntu1


The crash can be reproduced some of the time.

 -- Backtrace:
Application: System Settings (systemsettings), signal: Segmentation fault
[Current thread is 1 (Thread 0xb781f760 (LWP 8261))]

Thread 2 (Thread 0xb4fb4b70 (LWP 8262)):
#0  0x00bce344 in __pthread_mutex_unlock_usercnt () from /lib/tls/i686/cmov/libpthread.so.0
#1  0x00a9bb76 in pthread_mutex_unlock () from /lib/tls/i686/cmov/libc.so.6
#2  0x0864624b in g_main_context_release () from /lib/libglib-2.0.so.0
#3  0x08648143 in ?? () from /lib/libglib-2.0.so.0
#4  0x08648518 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#5  0x04ff159f in QEventDispatcherGlib::processEvents (this=0x9522ae0, flags=...) at kernel/qeventdispatcher_glib.cpp:414
#6  0x04fc3ff9 in QEventLoop::processEvents (this=0xb4fb4240, flags=) at kernel/qeventloop.cpp:149
#7  0x04fc444a in QEventLoop::exec (this=0xb4fb4240, flags=...) at kernel/qeventloop.cpp:201
#8  0x04ec05a8 in QThread::exec (this=0x9535668) at thread/qthread.cpp:487
#9  0x04fa3bcb in QInotifyFileSystemWatcherEngine::run (this=0x9535668) at io/qfilesystemwatcher_inotify.cpp:248
#10 0x04ec332e in QThreadPrivate::start (arg=0x9535668) at thread/qthread_unix.cpp:248
#11 0x00bca96e in start_thread () from /lib/tls/i686/cmov/libpthread.so.0
#12 0x00a8e9de in clone () from /lib/tls/i686/cmov/libc.so.6

Thread 1 (Thread 0xb781f760 (LWP 8261)):
[KCrash Handler]
#6  0x012ecbda in QDialog::result (this=0x9628d78) at dialogs/qdialog.cpp:432
#7  0x05e44b0f in ?? () from /usr/lib/kde4/kcm_kpk_addrm.so
#8  0x05e450cb in ?? () from /usr/lib/kde4/kcm_kpk_addrm.so
#9  0x04fcac3a in QMetaObject::metacall (object=0x9584f38, cl=QMetaObject::ReadProperty, idx=-1080442624, argv=0x9628d78) at kernel/qmetaobject.cpp:237
#10 0x04fd9375 in QMetaObject::activate (sender=0x9588e88, m=0x5e51a10, local_signal_index=1, argv=0x0) at kernel/qobject.cpp:3293
#11 0x05e416a7 in ?? () from /usr/lib/kde4/kcm_kpk_addrm.so
#12 0x009911da in KCModuleProxy::save (this=0x9482ac0) at ../../kutils/kcmoduleproxy.cpp:279
#13 0x00b42f03 in ModuleView::moduleSave (this=0x948e4d8, module=0x93ee3e8) at ../../../systemsettings/core/ModuleView.cpp:302
#14 0x00b434b9 in ModuleView::moduleSave (this=0x948e4d8) at ../../../systemsettings/core/ModuleView.cpp:293
#15 0x00b46803 in ModuleView::qt_metacall (this=0x948e4d8, _c=QMetaObject::InvokeMetaMethod, _id=5, _a=0xbf99c438) at ./ModuleView.moc:95
#16 0x04fcac3a in QMetaObject::metacall (object=0x948e4d8, cl=QMetaObject::ReadProperty, idx=32, argv=0xbf99c438) at kernel/qmetaobject.cpp:237
#17 0x04fd9375 in QMetaObject::activate (sender=0x9492c40, m=0x16ea8c4, local_signal_index=2, argv=0xbf99c438) at kernel/qobject.cpp:3293
#18 0x014da2d9 in QAbstractButton::clicked (this=0x9492c40, _t1=false) at .moc/release-shared/moc_qabstractbutton.cpp:206
#19 0x011b9ce9 in QAbstractButtonPrivate::emitClicked (this=0x9494d30) at widgets/qabstractbutton.cpp:546
#20 0x011bab34 in QAbstractButtonPrivate::click (this=0x9494d30) at widgets/qabstractbutton.cpp:539
#21 0x011badee in QAbstractButton::mouseReleaseEvent (this=0x9492c40, e=0xbf99cb70) at widgets/qabstractbutton.cpp:1121
#22 0x00e0d788 in QWidget::event (this=0x9492c40, event=0xbf99cb70) at kernel/qwidget.cpp:7998
#23 0x011b9b8e in QAbstractButton::event (this=0x9492c40, e=0x93ee3e8) at widgets/qabstractbutton.cpp:1080
#24 0x01264032 in QPushButton::event (this=0x9492c40, e=0xbf99cb70) at widgets/qpushbutton.cpp:679
#25 0x00daf4dc in QApplicationPrivate::notify_helper (this=0x9209490, receiver=0x9492c40, e=0xbf99cb70) at kernel/qapplication.cpp:4300
#26 0x00db69f7 in QApplication::notify (this=0xbf99d42c, receiver=0x9492c40, e=0xbf99cb70) at kernel/qapplication.cpp:3865
#27 0x003f7efa in KApplication::notify (this=0xbf99d42c, receiver=0x9492c40, event=0xbf99cb70) at ../../kdeui/kernel/kapplication.cpp:302
#28 0x04fc59db in QCoreApplication::notifyInternal (this=0xbf99d42c, receiver=0x9492c40, event=0xbf99cb70) at kernel/qcoreapplication.cpp:704
#29 0x00db5952 in QCoreApplication::sendEvent (receiver=0x9492c40, event=0xbf99cb70, alienWidget=0x9492c40, nativeWidget=0x926c4a0, buttonDown=0x16f3058, lastMouseReceiver=..., spontaneous=true)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#30 QApplicationPrivate::sendMouseEvent (receiver=0x9492c40, event=0xbf99cb70, alienWidget=0x9492c40, nativeWidget=0x926c4a0, buttonDown=0x16f3058, lastMouseReceiver=..., spontaneous=true)
    at kernel/qapplication.cpp:2965
#31 0x00e41018 in QETWidget::translateMouseEvent (this=0x926c4a0, event=0xbf99d08c) at kernel/qapplication_x11.cpp:4368
#32 0x00e404a1 in QApplication::x11ProcessEvent (this=0xbf99d42c, event=0xbf99d08c) at kernel/qapplication_x11.cpp:3379
#33 0x00e6f43a in x11EventSourceDispatch (s=0x920c0b0, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#34 0x08644645 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#35 0x08648338 in ?? () from /lib/libglib-2.0.so.0
#36 0x08648518 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#37 0x04ff1565 in QEventDispatcherGlib::processEvents (this=0x91e7520, flags=...) at kernel/qeventdispatcher_glib.cpp:412
#38 0x00e6ef65 in QGuiEventDispatcherGlib::processEvents (this=0x91e7520, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#39 0x04fc3ff9 in QEventLoop::processEvents (this=0xbf99d384, flags=) at kernel/qeventloop.cpp:149
#40 0x04fc444a in QEventLoop::exec (this=0xbf99d384, flags=...) at kernel/qeventloop.cpp:201
#41 0x04fc863f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:981
#42 0x00daf577 in QApplication::exec () at kernel/qapplication.cpp:3579
#43 0x08056b5e in main (argc=5, argv=0xbf99d574) at ../../../systemsettings/app/main.cpp:49

Reported using DrKonqi