Application: kwin (4.6.2 (4.6.2))
KDE Platform Version: 4.6.2 (4.6.2)
Qt Version: 4.7.2
Operating System: Linux 2.6.38-11-generic x86_64
Distribution: Ubuntu 11.04

-- Information about the crash:
- What I was doing when the application crashed:
Loading desktop with new graphics drivers and new version of xserver.

-- Backtrace:
Application: KWin (kwin), signal: Aborted
[KCrash Handler]
#6  0x00007f3aea62ad05 in raise (sig=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#7  0x00007f3aea62eab6 in abort () at abort.c:92
#8  0x00007f3aea6237c5 in __assert_fail (assertion=0x7f3ae846bb9a "!dpy->xcb->reply_data", file=<value optimized out>, line=515, function=<value optimized out>) at assert.c:81
#9  0x00007f3ae83f7bcf in _XReply () from /usr/lib/x86_64-linux-gnu/libX11.so.6
#10 0x00007f3aead64c76 in ?? () from /usr/lib/libGL.so.1
#11 0x00007f3aead42e88 in ?? () from /usr/lib/libGL.so.1
#12 0x00007f3aead3d6ca in glXQueryVersion () from /usr/lib/libGL.so.1
#13 0x00007f3aeaa6cfbe in KWin::CompositingPrefs::detect (this=0x7fffb773c160) at ../../kwin/compositingprefs.cpp:142
#14 0x00007f3aea9faf06 in KWin::Options::reloadCompositingSettings (this=0x145d540) at ../../kwin/options.cpp:300
#15 0x00007f3aea9ffffb in KWin::Options::updateSettings (this=0x145d540) at ../../kwin/options.cpp:274
#16 0x00007f3aea9e2366 in KWin::Application::Application (this=0x7fffb773d6b0) at ../../kwin/main.cpp:327
#17 0x00007f3aea9e3e7d in kdemain (argc=<value optimized out>, argv=0x7fffb773dd48) at ../../kwin/main.cpp:516
#18 0x00007f3aea615eff in __libc_start_main (main=0x400740 <main(int, char**)>, argc=3, ubp_av=0x7fffb773dd48, init=<value optimized out>, fini=<value optimized out>, rtld_fini=<value optimized out>, stack_end=0x7fffb773dd38) at libc-start.c:226
#19 0x0000000000400669 in _start ()

Reported using DrKonqi