Application that crashed: kontact
Version of the application: 4.3.0 pre
KDE Version: 4.2.90 (KDE 4.2.90 (KDE 4.3 Beta2))
Qt Version: 4.5.1
Operating System: Linux 2.6.28-11-generic x86_64
Distribution: Ubuntu 9.04

What I was doing when the application crashed:
Sometimes when I use kontact to read news (akregator), it crashes at the time I press alt+left to go back while browesing

 -- Backtrace:
Application: Kontact (kontact), signal: Segmentation fault
[KCrash Handler]
#5  QWidget::effectiveWinId (this=0x1c5d7f0) at ../../include/QtGui/../../src/gui/kernel/qwidget.h:234
#6  0x00007f4dc1ebc691 in qt_x11_enforce_cursor (w=0x3985350, force=false) at kernel/qwidget_x11.cpp:306
#7  0x00007f4dc1ebc83d in QWidgetPrivate::unsetCursor_sys (this=<value optimized out>) at kernel/qwidget_x11.cpp:1248
#8  0x00007f4dc1e82221 in QWidget::unsetCursor (this=0x3985350) at kernel/qwidget.cpp:4619
#9  0x00007f4dc63fd084 in KHTMLView::clear (this=0x39fd050) at /build/buildd/kde4libs-4.2.90/khtml/khtmlview.cpp:629
#10 0x00007f4dc6420643 in KHTMLPart::clear (this=0x3d683b0) at /build/buildd/kde4libs-4.2.90/khtml/khtml_part.cpp:1569
#11 0x00007f4dc642d46e in KHTMLPart::restoreState (this=0x3d683b0, stream=@0x7fffced8f110) at /build/buildd/kde4libs-4.2.90/khtml/khtml_part.cpp:5446
#12 0x00007f4d9f6c53bb in Akregator::BrowserFrame::Private::restoreHistoryEntry (this=0x3444490, entry=@0x7fffced8f1c0) at /build/buildd/kdepim-4.2.90/akregator/src/browserframe_p.cpp:156
#13 0x00007f4d9f6c0fcd in Akregator::BrowserFrame::slotHistoryBack (this=0x3212f40) at /build/buildd/kdepim-4.2.90/akregator/src/browserframe.cpp:332
#14 0x00007f4d9f6c0b45 in Akregator::FrameManager::qt_metacall (this=0x3090310, _c=QMetaObject::InvokeMetaMethod, _id=<value optimized out>, _a=0x7fffced8f2f0)
    at /build/buildd/kdepim-4.2.90/obj-x86_64-linux-gnu/akregator/src/framemanager.moc:152
#15 0x00007f4dc12ca8d2 in QMetaObject::activate (sender=0x30a2220, from_signal_index=<value optimized out>, to_signal_index=6, argv=0x3141560) at kernel/qobject.cpp:3120
#16 0x00007f4dc1e2bb87 in QAction::triggered (this=0x1c5d7f0, _t1=false) at .moc/release-shared/moc_qaction.cpp:236
#17 0x00007f4dc1e2d000 in QAction::activate (this=0x30a2220, event=<value optimized out>) at kernel/qaction.cpp:1160
#18 0x00007f4dc1e2fb17 in QAction::event (this=0x1c5d7f0, e=<value optimized out>) at kernel/qaction.cpp:1079
#19 0x00007f4dc318e253 in KAction::event (this=0x1c5d7f0, event=0x7fffced8f880) at /build/buildd/kde4libs-4.2.90/kdeui/actions/kaction.cpp:88
#20 0x00007f4dc1e31b9d in QApplicationPrivate::notify_helper (this=0x187f540, receiver=0x30a2220, e=0x7fffced8f880) at kernel/qapplication.cpp:4057
#21 0x00007f4dc1e39dea in QApplication::notify (this=0x7fffced91f80, receiver=0x30a2220, e=0x7fffced8f880) at kernel/qapplication.cpp:4022
#22 0x00007f4dc326106b in KApplication::notify (this=0x7fffced91f80, receiver=0x30a2220, event=0x7fffced8f880) at /build/buildd/kde4libs-4.2.90/kdeui/kernel/kapplication.cpp:302
#23 0x00007f4dc12b4dfc in QCoreApplication::notifyInternal (this=0x7fffced91f80, receiver=0x30a2220, event=0x7fffced8f880) at kernel/qcoreapplication.cpp:610
#24 0x00007f4dc1e6750d in QShortcutMap::dispatchEvent (this=<value optimized out>, e=0x7fffced8fd80) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:213
#25 0x00007f4dc1e6936c in QShortcutMap::tryShortcutEvent (this=0x187f658, o=<value optimized out>, e=0x7fffced8fd80) at kernel/qshortcutmap.cpp:369
#26 0x00007f4dc1e3ae11 in QApplication::notify (this=0x7fffced91f80, receiver=0x308eea0, e=0x7fffced8fd80) at kernel/qapplication.cpp:3646
#27 0x00007f4dc326106b in KApplication::notify (this=0x7fffced91f80, receiver=0x308eea0, event=0x7fffced8fd80) at /build/buildd/kde4libs-4.2.90/kdeui/kernel/kapplication.cpp:302
#28 0x00007f4dc12b4dfc in QCoreApplication::notifyInternal (this=0x7fffced91f80, receiver=0x308eea0, event=0x7fffced8fd80) at kernel/qcoreapplication.cpp:610
#29 0x00007f4dc1ec71d4 in QKeyMapper::sendKeyEvent (keyWidget=0x308eea0, grab=<value optimized out>, type=QEvent::KeyPress, code=16777234, modifiers={i = -824639568}, text=@0x7fffced8ffa0, 
    autorepeat=false, count=1, nativeScanCode=113, nativeVirtualKey=65361, nativeModifiers=8) at kernel/qkeymapper_x11.cpp:1675
#30 0x00007f4dc1ec9532 in QKeyMapperPrivate::translateKeyEvent (this=0x18b8d30, keyWidget=0x308eea0, event=0x7fffced91bb0, grab=60) at kernel/qkeymapper_x11.cpp:1645
#31 0x00007f4dc1ea1d7e in QApplication::x11ProcessEvent (this=0x7fffced91f80, event=0x7fffced91bb0) at kernel/qapplication_x11.cpp:3459
#32 0x00007f4dc1ecaf84 in x11EventSourceDispatch (s=0x1878820, callback=0, user_data=0x0) at kernel/qguieventdispatcher_glib.cpp:146
#33 0x00007f4dbaa0820a in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#34 0x00007f4dbaa0b8e0 in ?? () from /usr/lib/libglib-2.0.so.0
#35 0x00007f4dbaa0ba7c in g_main_context_iteration () from /usr/lib/libglib-2.0.so.0
#36 0x00007f4dc12de52f in QEventDispatcherGlib::processEvents (this=0x1844ea0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:324
#37 0x00007f4dc1eca70f in QGuiEventDispatcherGlib::processEvents (this=0x1c5d7f0, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:202
#38 0x00007f4dc12b36a2 in QEventLoop::processEvents (this=<value optimized out>, flags={i = -824631648}) at kernel/qeventloop.cpp:149
#39 0x00007f4dc12b3a6d in QEventLoop::exec (this=0x7fffced91ee0, flags={i = -824631568}) at kernel/qeventloop.cpp:200
#40 0x00007f4dc12b5d34 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:888
#41 0x0000000000404945 in main (argc=1, argv=0x7fffced92668) at /build/buildd/kdepim-4.2.90/kontact/src/main.cpp:218

Reported using DrKonqi