Application that crashed: kwin
Version of the application: 4.2.3 (KDE 4.2.3)
KDE Version: 4.2.3 (KDE 4.2.3)
Qt Version: 4.5.1
Operating System: Linux 2.6.30_rc7-119 i686
Distribution: "Pardus 2009 Alpha"

What I was doing when the application crashed:
Sometimes KWin crashes while I was switching between windows with cover switch effect. I can't reproduce it everytime I switch between windows.

 -- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
[KCrash Handler]
#6  KWin::WindowPaintData::WindowPaintData(struct KWin::EffectWindow *) (this=0xbfe086a0, w=0x44a6e000)
    at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/lib/kwineffects.cpp:74
#7  0xb345f082 in KWin::CoverSwitchEffect::paintWindows (this=0x83324e0, windows=0x8332540, left=true, reflectedWindows=false, additionalWindow=0x0)
    at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects/coverswitch.cpp:911
#8  0xb345fb1e in KWin::CoverSwitchEffect::paintScene (this=0x83324e0, frontWindow=0x84d19b0, leftWindows=0x8332540, rightWindows=0x8332544, reflectedWindows=false)
    at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects/coverswitch.cpp:468
#9  0xb3460ffa in KWin::CoverSwitchEffect::paintScreen (this=0x83324e0, mask=32, region={d = 0xbfe08b28, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects/coverswitch.cpp:298
#10 0xb80bb60b in KWin::EffectsHandlerImpl::paintScreen (this=0x84d2898, mask=32, region={d = 0xbfe08b68, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects.cpp:122
#11 0xb7ac5644 in KWin::Effect::paintScreen (this=0x82c6b20, mask=32, region={d = 0xbfe08ba8, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/lib/kwineffects.cpp:199
#12 0xb80bb60b in KWin::EffectsHandlerImpl::paintScreen (this=0x84d2898, mask=32, region={d = 0xbfe08be8, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects.cpp:122
#13 0xb7ac5644 in KWin::Effect::paintScreen (this=0x89ff310, mask=32, region={d = 0xbfe08c28, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/lib/kwineffects.cpp:199
#14 0xb80bb60b in KWin::EffectsHandlerImpl::paintScreen (this=0x84d2898, mask=32, region={d = 0xbfe08cf4, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects.cpp:122
#15 0xb3457447 in KWin::ThumbnailAsideEffect::paintScreen (this=0x82334d8, mask=32, region=
        {d = 0xbfe08d38, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, data=@0xbfe08e78)
    at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects/thumbnailaside.cpp:56
#16 0xb80bb60b in KWin::EffectsHandlerImpl::paintScreen (this=0x84d2898, mask=32, region={d = 0xbfe08d78, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects.cpp:122
#17 0xb7ac5644 in KWin::Effect::paintScreen (this=0x8369338, mask=32, region={d = 0xbfe08db8, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/lib/kwineffects.cpp:199
#18 0xb80bb60b in KWin::EffectsHandlerImpl::paintScreen (this=0x84d2898, mask=32, region={d = 0xbfe08df8, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects.cpp:122
#19 0xb3458a26 in KWin::ZoomEffect::paintScreen (this=0x84cb368, mask=32, region={d = 0xbfe08e38, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects/zoom.cpp:73
#20 0xb80bb60b in KWin::EffectsHandlerImpl::paintScreen (this=0x84d2898, mask=32, region={d = 0xbfe08ed0, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, 
    data=@0xbfe08e78) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/effects.cpp:122
#21 0xb80a9728 in KWin::Scene::paintScreen (this=0x847db50, mask=0xbfe08f3c, region=0xbfe08ff8) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/scene.cpp:133
#22 0xb80b2f65 in KWin::SceneOpenGL::paint (this=0x847db50, damage={d = 0xbfe08ff8, static shared_empty = {ref = {_q_value = 236}, rgn = 0x0, xrectangles = 0x0, qt_rgn = 0x0}}, toplevels=
        {{p = {static shared_null = {ref = {_q_value = 3725}, alloc = 0, begin = 0, end = 0, sharable = 1, array = {0x0}}, d = 0xbfe08ff4}, d = 0xbfe08ff4}})
    at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/scene_opengl.cpp:724
#23 0xb80a3860 in KWin::Workspace::performCompositing (this=0x837f520) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/composite.cpp:384
#24 0xb80445fd in KWin::Workspace::qt_metacall (this=0x837f520, _c=QMetaObject::InvokeMetaMethod, _id=140, _a=0xbfe090c8)
    at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/build/kwin/workspace.moc:446
#25 0xb6b119c4 in QMetaObject::activate(QObject*, int, int, void**) () from /usr/qt/4/lib/libQtCore.so.4
#26 0xb6b13235 in QMetaObject::activate(QObject*, QMetaObject const*, int, void**) () from /usr/qt/4/lib/libQtCore.so.4
#27 0xb6b4e675 in QTimer::timeout() () from /usr/qt/4/lib/libQtCore.so.4
#28 0xb6b176c6 in QTimer::timerEvent(QTimerEvent*) () from /usr/qt/4/lib/libQtCore.so.4
#29 0xb6b0bbfb in QObject::event(QEvent*) () from /usr/qt/4/lib/libQtCore.so.4
#30 0xb6d9543c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/qt/4/lib/libQtGui.so.4
#31 0xb6d9dbb5 in QApplication::notify(QObject*, QEvent*) () from /usr/qt/4/lib/libQtGui.so.4
#32 0xb7cc91dd in KApplication::notify (this=0xbfe09840, receiver=0x837f774, event=0xbfe0956c) at /var/pisi/kdelibs-4.2.3-43/work/kdelibs-4.2.3/kdeui/kernel/kapplication.cpp:307
#33 0xb805e43c in KWin::Application::notify (this=0xbfe09840, o=0x837f774, e=0xbfe0956c) at /var/pisi/kdebase-workspace-4.2.3-58/work/kdebase-workspace-4.2.3/kwin/main.cpp:368
#34 0xb6afaefe in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/qt/4/lib/libQtCore.so.4
#35 0xb6b2b4bd in ?? () from /usr/qt/4/lib/libQtCore.so.4
#36 0xb6b27dae in ?? () from /usr/qt/4/lib/libQtCore.so.4
#37 0xb55f0b0c in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#38 0x081fc094 in ?? ()
#39 0x081fcf00 in ?? ()
#40 0xb566e3b8 in ?? () from /usr/lib/libglib-2.0.so.0
#41 0xb566e3e0 in ?? () from /usr/lib/libglib-2.0.so.0
#42 0xb6b27d90 in ?? () from /usr/qt/4/lib/libQtCore.so.4
#43 0x00000000 in ?? ()