Backtrace:
[ 28176.789] 0: /usr/bin/X (xorg_backtrace+0x3c) [0x80de1c8]
[ 28176.789] 1: /usr/bin/X (0x8047000+0x59b2b) [0x80a0b2b]
[ 28176.789] 2: (vdso) (__kernel_rt_sigreturn+0x0) [0xffffe40c]
[ 28176.789] 3: /usr/lib/xorg/modules/libexa.so (0xb75e5000+0xacf6) [0xb75efcf6]
[ 28176.789] 4: /usr/bin/X (0x8047000+0x14e0c9) [0x81950c9]
[ 28176.789] 5: /usr/lib/xorg/modules/extensions/libglx.so (0xb7651000+0x3295c) [0xb768395c]
[ 28176.789] 6: /usr/lib/dri/swrast_dri.so (0xb7322000+0x106b0) [0xb73326b0]
[ 28176.789] 7: /usr/lib/dri/swrast_dri.so (0xb7322000+0x106ec) [0xb73326ec]
[ 28176.789] 8: /usr/lib/xorg/modules/extensions/libglx.so (0xb7651000+0x328d7) [0xb76838d7]
[ 28176.789] 9: /usr/lib/xorg/modules/extensions/libglx.so (0xb7651000+0x2f40d) [0xb768040d]
[ 28176.789] 10: /usr/lib/xorg/modules/extensions/libglx.so (0xb7651000+0x301ab) [0xb76811ab]
[ 28176.789] 11: /usr/lib/xorg/modules/extensions/libglx.so (0xb7651000+0x31faa) [0xb7682faa]
[ 28176.789] 12: /usr/bin/X (0x8047000+0x27199) [0x806e199]
[ 28176.789] 13: /usr/bin/X (0x8047000+0x1b29a) [0x806229a]
[ 28176.789] 14: /lib/libc.so.6 (__libc_start_main+0xe7) [0x42898b83]
[ 28176.789] 15: /usr/bin/X (0x8047000+0x1ae81) [0x8061e81]
[ 28176.789] Segmentation fault at address (nil)
[ 28176.789].
Fatal server error:
[ 28176.789] Caught signal 11 (Segmentation fault). Server aborting
[ 28176.789].
[ 28176.789].
Please consult the The X.Org Foundation support.