backtrace:
0: /usr/bin/Xorg(xf86SigHandler+0x85) [0x80c3b35]
1: [0xb7f9b420]
2: /lib/i686/libc.so.6(memcpy+0x1c) [0xb7d60bac]
3: /usr/lib/xorg/modules/extensions//libGLcore.so(_mesa_initialize_context+0x54) [0xaf807b14]
4: /usr/lib/xorg/modules/extensions//libGLcore.so(XMesaCreateContext+0x99) [0xaf95c629]
5: /usr/lib/xorg/modules/extensions//libGLcore.so [0xaf95a15f]
6: /usr/lib/xorg/modules/extensions//libglx.so(DoCreateContext+0x12c) [0xb7c1449c]
7: /usr/lib/xorg/modules/extensions//libglx.so [0xb7c14683]
8: /usr/lib/xorg/modules/extensions//libglx.so [0xb7c169c9]
9: /usr/bin/Xorg [0x8151517]
10: /usr/bin/Xorg(Dispatch+0x19f) [0x808986f]
11: /usr/bin/Xorg(main+0x495) [0x8071045]
12: /lib/i686/libc.so.6(__libc_start_main+0xdc) [0xb7d09d8c]
13: /usr/bin/Xorg(FontFileCompleteXLFD+0x1e5) [0x8070371]