Comment 7 for bug 937347

the issue is a fglrx driver one:

[ 4357.528] 0: /usr/bin/X (xorg_backtrace+0x26) [0x7f4c86e732f6]
[ 4357.528] 1: /usr/bin/X (0x7f4c86ceb000+0x18c19a) [0x7f4c86e7719a]
[ 4357.528] 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7f4c86011000+0xfcb0) [0x7f4c86020cb0]
[ 4357.528] 3: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/extra-modules.dpkg-tmp/modules/drivers/fglrx_drv.so (xs111LookupPrivate+0x22) [0x7f4c82ca8c72]
[ 4357.528] 4: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/extra-modules.dpkg-tmp/modules/drivers/fglrx_drv.so (xclLookupPrivate+0xd) [0x7f4c8267b75d]
[ 4357.528] 5: /usr/lib/x86_64-linux-gnu/xorg/extra-modules/extra-modules.dpkg-tmp/modules/amdxmm.so (X740XvPutImage+0x12e) [0x7f4c7ebe88de]
[ 4357.528] 6: /usr/bin/X (0x7f4c86ceb000+0xa6bfe) [0x7f4c86d91bfe]
[ 4357.528] 7: /usr/lib/xorg/modules/extensions/libextmod.so (0x7f4c83d8e000+0xecb2) [0x7f4c83d9ccb2]
[ 4357.528] 8: /usr/bin/X (0x7f4c86ceb000+0x4e721) [0x7f4c86d39721]
[ 4357.528] 9: /usr/bin/X (0x7f4c86ceb000+0x3d64a) [0x7f4c86d2864a]
[ 4357.528] 10: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xed) [0x7f4c84ea876d]
[ 4357.529] 11: /usr/bin/X (0x7f4c86ceb000+0x3d93d) [0x7f4c86d2893d]