Application that crashed: kpackagekit
Version of the application: 0.4.2
KDE Version: 4.3.2 (KDE 4.3.2)
Qt Version: 4.5.2
Operating System: Linux 2.6.31-15-generic i686
Distribution: Ubuntu 9.10

What I was doing when the application crashed:
I clicked on Update Notifier, which told me I have few updates availible. Then in KPackageKit i selected all availabe updates and pressed OK button (*not* Apply). Small window appeared (this one which always appears when you apply updates) and suddenly it crashed, but after a while system notified (in the same place as update notifier did), that "newly updated software needs your system to be rebooted before it can be used", as it would do after this update. It must be emphasized, that it only occurs when pressing OK, never when pressing Apply before that.

 -- Backtrace:
Application: KPackageKit (kpackagekit), signal: Segmentation fault
[KCrash Handler]
#6  QWidget::window (this=0x92669e0) at kernel/qwidget.cpp:3883
#7  0xb67f4d2e in QApplicationPrivate::dispatchEnterLeave (enter=0x911e560, leave=0x92669e0) at kernel/qapplication.cpp:2527
#8  0xb67f517a in QApplicationPrivate::sendMouseEvent (receiver=0x911e560, event=0xbfa006c0, alienWidget=0x911e560, nativeWidget=0x90b76f8, buttonDown=0xb7068aa0, lastMouseReceiver=...)
    at kernel/qapplication.cpp:2908
#9  0xb68637c0 in QETWidget::translateMouseEvent (this=0x90b76f8, event=0xbfa01d0c) at kernel/qapplication_x11.cpp:4409
#10 0xb6862c4b in QApplication::x11ProcessEvent (this=0xbfa020a0, event=0xbfa01d0c) at kernel/qapplication_x11.cpp:3428
#11 0xb688f502 in x11EventSourceDispatch (s=0x9028368, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#12 0xb5a10e78 in g_main_dispatch (context=0x9027690) at /build/buildd/glib2.0-2.22.2/glib/gmain.c:1960
#13 IA__g_main_context_dispatch (context=0x9027690) at /build/buildd/glib2.0-2.22.2/glib/gmain.c:2513
#14 0xb5a14720 in g_main_context_iterate (context=0x9027690, block=<value optimized out>, dispatch=1, self=0x902a980) at /build/buildd/glib2.0-2.22.2/glib/gmain.c:2591
#15 0xb5a14853 in IA__g_main_context_iteration (context=0x9027690, may_block=1) at /build/buildd/glib2.0-2.22.2/glib/gmain.c:2654
#16 0xb658302c in QEventDispatcherGlib::processEvents (this=0x9007f08, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#17 0xb688ebe5 in QGuiEventDispatcherGlib::processEvents (this=0x9007f08, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#18 0xb6556c79 in QEventLoop::processEvents (this=0xbfa02004, flags=) at kernel/qeventloop.cpp:149
#19 0xb65570ca in QEventLoop::exec (this=0xbfa02004, flags=...) at kernel/qeventloop.cpp:201
#20 0xb655953f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#21 0xb67eddd7 in QApplication::exec () at kernel/qapplication.cpp:3525
#22 0x0804e47b in _start ()

Reported using DrKonqi