Application: kwin (4.6.5 (4.6.5))
KDE Platform Version: 4.6.5 (4.6.5) (Compiled from sources)
Qt Version: 4.7.3
Operating System: Linux 2.6.39.3 i686
Distribution (Platform): Gentoo Packages

-- Information about the crash:
- What I was doing when the application crashed:
I changed the Scale method from "Accurate" to "Smooth" in Desktop Effects -> Advanced

-- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
[Current thread is 1 (Thread 0xb1c52720 (LWP 11467))]

Thread 2 (Thread 0xaed89b70 (LWP 11472)):
#0  0xb77aa424 in __kernel_vsyscall ()
#1  0xb584c51c in pthread_cond_wait () at ../nptl/sysdeps/unix/sysv/linux/i386/i686/../i486/pthread_cond_wait.S:169
#2  0xb75c2f5e in __pthread_cond_wait (cond=0xb6db0290, mutex=0xb6db0278) at forward.c:139
#3  0xb6caade7 in QTWTF::TCMalloc_PageHeap::scavengerThread (this=0xb6dab1a0) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:2359
#4  0xb6caae31 in QTWTF::TCMalloc_PageHeap::runScavengerThread (context=0xb6dab1a0) at ../3rdparty/javascriptcore/JavaScriptCore/wtf/FastMalloc.cpp:1464
#5  0xb5847d23 in start_thread (arg=0xaed89b70) at pthread_create.c:301
#6  0xb75b5bfe in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:133

Thread 1 (Thread 0xb1c52720 (LWP 11467)):
[KCrash Handler]
#7  0xb384f586 in xcb_glx_get_string_string_length () from /usr/lib/libxcb-glx.so.0
#8  0xb691eea9 in __glXGetString (dpy=0x876d4a8, opcode=153, contextTag=10027013, name=7939) at glx_query.c:82
#9  0xb691b68c in __indirect_glGetString (name=7939) at single2.c:685
#10 0xb68ff564 in indirect_bind_context (gc=0x8866798, old=0x887dd90, draw=23082867, read=23082867) at indirect_glx.c:156
#11 0xb68fca21 in MakeContextCurrent (dpy=0x876d4a8, draw=23082867, read=23082867, gc_user=0x8866798) at glxcurrent.c:265
#12 0xb68fcb93 in glXMakeCurrent (dpy=0x876d4a8, draw=23082867, gc=0x8866798) at glxcurrent.c:289
#13 0xb77215a4 in KWin::SceneOpenGL::initRenderingContext (this=0x891f208) at /var/tmp/portage/kde-base/kwin-4.6.5/work/kwin-4.6.5/kwin/scene_opengl.cpp:352
#14 0xb7726b77 in KWin::SceneOpenGL::SceneOpenGL (this=0x891f208, ws=0x87eceb0) at /var/tmp/portage/kde-base/kwin-4.6.5/work/kwin-4.6.5/kwin/scene_opengl.cpp:143
#15 0xb770a821 in KWin::Workspace::setupCompositing (this=0x87eceb0) at /var/tmp/portage/kde-base/kwin-4.6.5/work/kwin-4.6.5/kwin/composite.cpp:161
#16 0xb766abe1 in KWin::Workspace::slotReinitCompositing (this=0x87eceb0) at /var/tmp/portage/kde-base/kwin-4.6.5/work/kwin-4.6.5/kwin/workspace.cpp:1221
#17 0xb76765e1 in KWin::Workspace::qt_metacall (this=0x87eceb0, _c=QMetaObject::InvokeMetaMethod, _id=143, _a=0xbfcd6bc8) at /var/tmp/portage/kde-base/kwin-4.6.5/work/kwin-4.6.5_build/kwin/workspace.moc:552
#18 0xb5b1cbc1 in QDBusConnectionPrivate::deliverCall (this=0x874fcb0, object=0x87eceb0, msg=..., metaTypes=..., slotIdx=143) at qdbusintegrator.cpp:941
#19 0xb5b27327 in QDBusCallDeliveryEvent::placeMetaCall (this=0x8866580, object=0x87eceb0) at qdbusintegrator_p.h:103
#20 0xb59d9a9a in QObject::event (this=0x87eceb0, e=0x0) at kernel/qobject.cpp:1217
#21 0xb5f680a4 in QApplicationPrivate::notify_helper (this=0x8759cb8, receiver=0x87eceb0, e=0x8866580) at kernel/qapplication.cpp:4462
#22 0xb5f6d85e in QApplication::notify (this=0xbfcd74b4, receiver=0x87eceb0, e=0x8866580) at kernel/qapplication.cpp:3862
#23 0xb72f36fb in KApplication::notify (this=0xbfcd74b4, receiver=0x87eceb0, event=0x8866580) at /var/tmp/portage/kde-base/kdelibs-4.6.5/work/kdelibs-4.6.5/kdeui/kernel/kapplication.cpp:311
#24 0xb7692a30 in KWin::Application::notify (this=0xbfcd74b4, o=0x87eceb0, e=0x8866580) at /var/tmp/portage/kde-base/kwin-4.6.5/work/kwin-4.6.5/kwin/main.cpp:376
#25 0xb59c6de2 in QCoreApplication::notifyInternal (this=0xbfcd74b4, receiver=0x87eceb0, event=0x8866580) at kernel/qcoreapplication.cpp:731
#26 0xb59ca0f3 in sendEvent (receiver=0x0, event_type=0, data=0x8739bc0) at kernel/qcoreapplication.h:215
#27 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x8739bc0) at kernel/qcoreapplication.cpp:1372
#28 0xb59ca25e in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1265
#29 0xb602a5d2 in sendPostedEvents (this=0x8739900, flags=...) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#30 QEventDispatcherX11::processEvents (this=0x8739900, flags=...) at kernel/qeventdispatcher_x11.cpp:75
#31 0xb59c584a in QEventLoop::processEvents (this=0xbfcd73e4, flags=) at kernel/qeventloop.cpp:149
#32 0xb59c5cca in QEventLoop::exec (this=0xbfcd73e4, flags=...) at kernel/qeventloop.cpp:201
#33 0xb59ca321 in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1008
#34 0xb5f66d68 in QApplication::exec () at kernel/qapplication.cpp:3736
#35 0xb76958ac in kdemain (argc=3, argv=0xbfcd7724) at /var/tmp/portage/kde-base/kwin-4.6.5/work/kwin-4.6.5/kwin/main.cpp:542
#36 0x080486bb in main (argc=3, argv=0xbfcd7724) at /var/tmp/portage/kde-base/kwin-4.6.5/work/kwin-4.6.5_build/kwin/kwin_dummy.cpp:3

Reported using DrKonqi