Application that crashed: kaddressbook
Version of the application: 4.3
KDE Version: 4.3.1 (KDE 4.3.1)
Qt Version: 4.5.2
Operating System: Linux 2.6.30-1-686 i686

What I was doing when the application crashed:
I was playing around with "watched nicks" in Konversation and clicked "Add association" for a watched nick.  I then tried to "Edit contact" but could not because kaddressbook was not installed.
I installed kaddressbook, then attempted "Edit contact" again.  This opened kaddressbook -- two windows, a main window and a contact-editing menu.  I closed the main window by clicking on the X in the corner, then changed the name for my contact.  I clicked through the rest of the tabs, then clicked "OK" (or Save or whatever the button is called, I don't remember now).  That is when the crash happened.
I have not attempted to reproduce the crash.

 -- Backtrace:
Application: KAddressBook (kaddressbook), signal: Segmentation fault
[KCrash Handler]
#6  0xb60df4fb in KABC::AddressBook::findByUid (this=0x8c2f750, uid=...) at ../../kabc/addressbook.cpp:617
#7  0xb7f79518 in KABCore::contactModified(KABC::Addressee const&) () from /usr/lib/libkaddressbookprivate.so.4
#8  0xb7f8380d in KABCore::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib/libkaddressbookprivate.so.4
#9  0xb6d19b33 in QMetaObject::activate (sender=0x8b45f40, from_signal_index=73, to_signal_index=73, argv=0xbfa86e2c) at kernel/qobject.cpp:3112
#10 0xb6d1a782 in QMetaObject::activate (sender=0x8b45f40, m=0xb7fd7d68, local_signal_index=0, argv=0xbfa86e2c) at kernel/qobject.cpp:3186
#11 0xb7f4c613 in ?? () from /usr/lib/libkaddressbookprivate.so.4
#12 0xb7f4c818 in ?? () from /usr/lib/libkaddressbookprivate.so.4
#13 0xb7f4c9e6 in ?? () from /usr/lib/libkaddressbookprivate.so.4
#14 0xb6d19b33 in QMetaObject::activate (sender=0x8b45f40, from_signal_index=43, to_signal_index=43, argv=0x0) at kernel/qobject.cpp:3112
#15 0xb6d1a782 in QMetaObject::activate (sender=0x8b45f40, m=0xb7dd8644, local_signal_index=7, argv=0x0) at kernel/qobject.cpp:3186
#16 0xb7b9aec7 in KDialog::applyClicked (this=0x8b45f40) at ./kdialog.moc:240
#17 0xb7b9d52a in KDialog::slotButtonClicked (this=0x8b45f40, button=8) at ../../kdeui/dialogs/kdialog.cpp:857
#18 0xb7b9f7b2 in KDialog::qt_metacall (this=0x8b45f40, _c=QMetaObject::InvokeMetaMethod, _id=33, _a=0xbfa870bc) at ./kdialog.moc:184
#19 0xb7f4c96a in ?? () from /usr/lib/libkaddressbookprivate.so.4
#20 0xb6d19b33 in QMetaObject::activate (sender=0x8ed90e0, from_signal_index=4, to_signal_index=4, argv=0xbfa870bc) at kernel/qobject.cpp:3112
#21 0xb6d1a782 in QMetaObject::activate (sender=0x8ed90e0, m=0xb6df4d58, local_signal_index=0, argv=0xbfa870bc) at kernel/qobject.cpp:3186
#22 0xb6d1d3a3 in QSignalMapper::mapped (this=0x8ed90e0, _t1=8) at .moc/release-shared/moc_qsignalmapper.cpp:95
#23 0xb6d1dc2d in QSignalMapper::map (this=0x8ed90e0, sender=0x8bb4700) at kernel/qsignalmapper.cpp:266
#24 0xb6d1de1e in QSignalMapper::map (this=0x8ed90e0) at kernel/qsignalmapper.cpp:257
#25 0xb6d1e6eb in QSignalMapper::qt_metacall (this=0x8ed90e0, _c=QMetaObject::InvokeMetaMethod, _id=4, _a=0xbfa8723c) at .moc/release-shared/moc_qsignalmapper.cpp:81
#26 0xb6d19b33 in QMetaObject::activate (sender=0x8bb4700, from_signal_index=29, to_signal_index=30, argv=0xbfa8723c) at kernel/qobject.cpp:3112
#27 0xb6d19f60 in QMetaObject::activate (sender=0x8bb4700, m=0xb7a54924, from_local_signal_index=2, to_local_signal_index=3, argv=0xbfa8723c) at kernel/qobject.cpp:3206
#28 0xb786d9a1 in QAbstractButton::clicked (this=0x8bb4700, _t1=false) at .moc/release-shared/moc_qabstractbutton.cpp:200
#29 0xb7599379 in QAbstractButtonPrivate::emitClicked (this=0x8ef9360) at widgets/qabstractbutton.cpp:543
#30 0xb759af64 in QAbstractButtonPrivate::click (this=0x8ef9360) at widgets/qabstractbutton.cpp:536
#31 0xb759b1f6 in QAbstractButton::mouseReleaseEvent (this=0x8bb4700, e=0xbfa878dc) at widgets/qabstractbutton.cpp:1115
#32 0xb724177b in QWidget::event (this=0x8bb4700, event=0xbfa878dc) at kernel/qwidget.cpp:7549
#33 0xb759921e in QAbstractButton::event (this=0x8bb4700, e=0xbfa878dc) at widgets/qabstractbutton.cpp:1077
#34 0xb7642a50 in QPushButton::event (this=0x8bb4700, e=0xbfa878dc) at widgets/qpushbutton.cpp:662
#35 0xb71eb814 in QApplicationPrivate::notify_helper (this=0x8b45fd8, receiver=0x8bb4700, e=0xbfa878dc) at kernel/qapplication.cpp:4056
#36 0xb71f42e1 in QApplication::notify (this=0xbfa89138, receiver=0x8bb4700, e=0xbfa878dc) at kernel/qapplication.cpp:3758
#37 0xb7c344ad in KApplication::notify (this=0xbfa89138, receiver=0x8bb4700, event=0xbfa878dc) at ../../kdeui/kernel/kapplication.cpp:302
#38 0xb6d049cb in QCoreApplication::notifyInternal (this=0xbfa89138, receiver=0x8bb4700, event=0xbfa878dc) at kernel/qcoreapplication.cpp:610
#39 0xb71f336e in QCoreApplication::sendSpontaneousEvent (receiver=0x8bb4700, event=0xbfa878dc, alienWidget=0x8bb4700, nativeWidget=0x8b45f40, buttonDown=0xb7a61aa0, lastMouseReceiver=...)
    at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:216
#40 QApplicationPrivate::sendMouseEvent (receiver=0x8bb4700, event=0xbfa878dc, alienWidget=0x8bb4700, nativeWidget=0x8b45f40, buttonDown=0xb7a61aa0, lastMouseReceiver=...)
    at kernel/qapplication.cpp:2924
#41 0xb7261ea5 in QETWidget::translateMouseEvent (this=0x8b45f40, event=0xbfa88e8c) at kernel/qapplication_x11.cpp:4409
#42 0xb7261386 in QApplication::x11ProcessEvent (this=0xbfa89138, event=0xbfa88e8c) at kernel/qapplication_x11.cpp:3428
#43 0xb728b892 in x11EventSourceDispatch (s=0x8b48d00, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#44 0xb57ace98 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#45 0xb57b0623 in ?? () from /lib/libglib-2.0.so.0
#46 0xb57b07a8 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#47 0xb6d2f858 in QEventDispatcherGlib::processEvents (this=0x8b20160, flags=...) at kernel/qeventdispatcher_glib.cpp:327
#48 0xb728afd5 in QGuiEventDispatcherGlib::processEvents (this=0x8b20160, flags=...) at kernel/qguieventdispatcher_glib.cpp:202
#49 0xb6d0301a in QEventLoop::processEvents (this=0xbfa890f0, flags=...) at kernel/qeventloop.cpp:149
#50 0xb6d03462 in QEventLoop::exec (this=0xbfa890f0, flags=...) at kernel/qeventloop.cpp:201
#51 0xb6d058b9 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#52 0xb71eb697 in QApplication::exec () at kernel/qapplication.cpp:3525
#53 0x0804d484 in _start ()

Reported using DrKonqi