Application: kwin (4.6.5 (4.6.5))
KDE Platform Version: 4.6.5 (4.6.5)
Qt Version: 4.7.3
Operating System: Linux 2.6.32-5-amd64 x86_64
Distribution: Debian GNU/Linux 6.0.3 (squeeze)

-- Information about the crash:
- What I was doing when the application crashed:
 Changed the "mode OpenGL" to "shared memory". Because the image is to "float" mode was adopted. After the change in "safe mode" application KWin crashed.

-- Backtrace:
Application: KWin (kwin), signal: Segmentation fault
[KCrash Handler]
#6  __memcpy_sse2 () at ../sysdeps/x86_64/multiarch/../memcpy.S:267
#7  0x00007fdfd010bd4b in ?? () from /usr/lib/x86_64-linux-gnu/libGL.so.1
#8  0x00007fdfb773aaaf in KWin::ARBBlurShader::init (this=0x21becd0) at ../../../kwin/effects/blur/blurshader.cpp:473
#9  0x00007fdfb7737e1b in KWin::BlurEffect::reconfigure (this=0x21b8460, flags=<optimized out>) at ../../../kwin/effects/blur/blur.cpp:76
#10 0x00007fdfb7737fa7 in KWin::BlurEffect::BlurEffect (this=0x21b8460) at ../../../kwin/effects/blur/blur.cpp:48
#11 0x00007fdfb7738056 in KWin::effect_create_kwin4_effect_blur () at ../../../kwin/effects/blur/blur.cpp:29
#12 0x00007fdfd2c16471 in KWin::EffectsHandlerImpl::loadEffect (this=0x22a8540, name=...) at ../../kwin/effects.cpp:1128
#13 0x00007fdfd2c17531 in KWin::EffectsHandlerImpl::reconfigure (this=0x22a8540) at ../../kwin/effects.cpp:143
#14 0x00007fdfd2bf131a in KWin::Workspace::setupCompositing (this=0x24e7bc0) at ../../kwin/composite.cpp:216
#15 0x00007fdfd2b75733 in KWin::Workspace::Workspace (this=0x24e7bc0, restore=false) at ../../kwin/workspace.cpp:222
#16 0x00007fdfd2b8c7ca in KWin::Application::Application (this=<optimized out>) at ../../kwin/main.cpp:331
#17 0x00007fdfd2b8e4db in kdemain (argc=<optimized out>, argv=<optimized out>) at ../../kwin/main.cpp:506
#18 0x00007fdfd27ccead in __libc_start_main (main=<optimized out>, argc=<optimized out>, ubp_av=<optimized out>, init=<optimized out>, fini=<optimized out>, rtld_fini=<optimized out>, stack_end=0x7fffde8edad8) at libc-start.c:228
#19 0x00000000004006b1 in _start ()

Reported using DrKonqi