Version:            (using Devel)
Installed from:    Compiled sources

I own a Ati Radeon 9200 with the opensource radeon driver. Kwin works fine in composite mode, I can even play OpenGL games (for example Neverwinter Nights) but when exiting from the game, there's always a Kwin crash. Here a backtrace

Application: KWin (kwin), signal SIGSEGV
[Thread debugging using libthread_db enabled]
[New Thread 0xb67ea720 (LWP 10543)]
[KCrash handler]
#6  0xb7ee84da in KWin::Scene::Window::isOpaque ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#7  0xb7eea4f2 in KWin::Scene::paintSimpleScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#8  0xb7ee874b in KWin::Scene::finalPaintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#9  0xb7ef9a24 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#10 0xb50fbe14 in KWin::ShadowEffect::paintScreen ()
   from /media/hda3/kde/kde/lib/kde4/kwin4_effect_builtins.so
#11 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#12 0xb50dbbf0 in KWin::PresentWindowsEffect::paintScreen ()
   from /media/hda3/kde/kde/lib/kde4/kwin4_effect_builtins.so
#13 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#14 0xb7cf6f46 in KWin::Effect::paintScreen ()
   from /media/hda3/kde/kde/lib/libkwineffects.so.1
#15 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#16 0xb7cf6f46 in KWin::Effect::paintScreen ()
   from /media/hda3/kde/kde/lib/libkwineffects.so.1
#17 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#18 0xb50ccc2c in KWin::BoxSwitchEffect::paintScreen ()
   from /media/hda3/kde/kde/lib/kde4/kwin4_effect_builtins.so
#19 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#20 0xb50d0c19 in KWin::DesktopGridEffect::paintScreen ()
   from /media/hda3/kde/kde/lib/kde4/kwin4_effect_builtins.so
#21 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#22 0xb7cf6f46 in KWin::Effect::paintScreen ()
   from /media/hda3/kde/kde/lib/libkwineffects.so.1
#23 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#24 0xb7cf6f46 in KWin::Effect::paintScreen ()
   from /media/hda3/kde/kde/lib/libkwineffects.so.1
#25 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#26 0xb7cf6f46 in KWin::Effect::paintScreen ()
   from /media/hda3/kde/kde/lib/libkwineffects.so.1
#27 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#28 0xb50fe5d0 in KWin::TrackMouseEffect::paintScreen ()
   from /media/hda3/kde/kde/lib/kde4/kwin4_effect_builtins.so
#29 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#30 0xb7cf6f46 in KWin::Effect::paintScreen ()
   from /media/hda3/kde/kde/lib/libkwineffects.so.1
#31 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#32 0xb50eac2d in KWin::ZoomEffect::paintScreen ()
   from /media/hda3/kde/kde/lib/kde4/kwin4_effect_builtins.so
#33 0xb7ef99c1 in KWin::EffectsHandlerImpl::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#34 0xb7ee986e in KWin::Scene::paintScreen ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#35 0xb7ef3d8d in KWin::SceneOpenGL::paint ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#36 0xb7ee4faf in KWin::Workspace::performCompositing ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#37 0xb7e8b4d9 in KWin::Workspace::qt_metacall ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#38 0xb7a1d6ec in QMetaObject::activate (sender=0x80f2220, 
    from_signal_index=<value optimized out>, to_signal_index=4, argv=0x0)
    at /media/hda3/kde/src/qt-copy/src/corelib/kernel/qobject.cpp:3007
#39 0xb7a1daf2 in QMetaObject::activate (sender=0x80f2220, m=0xb7aaade4, 
    local_signal_index=0, argv=0x0)
    at /media/hda3/kde/src/qt-copy/src/corelib/kernel/qobject.cpp:3080
#40 0xb7a56437 in QTimer::timeout (this=0x80f2220)
    at .moc/release-shared/moc_qtimer.cpp:126
#41 0xb7a2606e in QTimer::timerEvent (this=0x80f2220, e=0xbfc18d28)
    at /media/hda3/kde/src/qt-copy/src/corelib/kernel/qtimer.cpp:263
#42 0xb7a1bc24 in QObject::event (this=0x80f2220, e=0xbfc18d28)
    at /media/hda3/kde/src/qt-copy/src/corelib/kernel/qobject.cpp:1105
#43 0xb71669cc in QApplicationPrivate::notify_helper (this=0x805a110, 
    receiver=0x80f2220, e=0xbfc18d28)
    at /media/hda3/kde/src/qt-copy/src/gui/kernel/qapplication.cpp:3766
#44 0xb716d3e9 in QApplication::notify (this=0xbfc18fb4, receiver=0x80f2220, 
    e=0xbfc18d28)
    at /media/hda3/kde/src/qt-copy/src/gui/kernel/qapplication.cpp:3360
#45 0xb6e89f7d in KApplication::notify ()
   from /media/hda3/kde/kde/lib/libkdeui.so.5
#46 0xb7e9e2dd in KWin::Application::notify ()
   from /media/hda3/kde/kde/lib/libkdeinit4_kwin.so
#47 0xb7a0cf99 in QCoreApplication::notifyInternal (this=0xbfc18fb4, 
    receiver=0x80f2220, event=0xbfc18d28)
    at /media/hda3/kde/src/qt-copy/src/corelib/kernel/qcoreapplication.cpp:583
#48 0xb7a35d61 in QTimerInfoList::activateTimers (this=0x805d184)
    at ../../include/QtCore/../../../../qt-copy/src/corelib/kernel/qcoreapplication.h:215
#49 0xb7a33880 in timerSourceDispatch (source=0x805d150)
    at /media/hda3/kde/src/qt-copy/src/corelib/kernel/qeventdispatcher_glib.cpp:166
#50 0xb6896bf8 in g_main_context_dispatch () from /usr/lib/libglib-2.0.so.0
#51 0xb6899e5e in ?? () from /usr/lib/libglib-2.0.so.0
#52 0x0805c490 in ?? ()
#53 0x00000000 in ?? ()
#0  0xb7f0d410 in __kernel_vsyscall ()