Comment 22 for bug 133677

You haven't attached your Xorg.0.log.old directly, only compressed.

I guess the important lines are:
(II) Open ACPI successful (/var/run/acpid.socket)
(II) AIGLX: Resuming AIGLX clients after VT switch
(II) intel(0): xf86BindGARTMemory: bind key 0 at 0x007bf000 (pgoffset 1983)
(II) intel(0): xf86BindGARTMemory: bind key 1 at 0x03038000 (pgoffset 12344)
(II) intel(0): xf86BindGARTMemory: bind key 2 at 0x04000000 (pgoffset 16384)
(II) intel(0): xf86BindGARTMemory: bind key 3 at 0x05000000 (pgoffset 20480)
(II) intel(0): xf86BindGARTMemory: bind key 4 at 0x08000000 (pgoffset 32768)
(WW) intel(0): ESR is 0x00000001, instruction error
(WW) intel(0): Existing errors found in hardware state.

Backtrace:
0: /usr/bin/X(xf86SigHandler+0x81) [0x80c9581]
1: [0xffffe420]
2: /usr/lib/xorg/modules/drivers//intel_drv.so [0xb7b69022]
3: /usr/bin/X(xf86CrtcSetMode+0x279) [0x80faf49]
4: /usr/bin/X(xf86SetDesiredModes+0x139) [0x80fb2f9]
5: /usr/lib/xorg/modules/drivers//intel_drv.so [0xb7b6c9e9]
6: /usr/lib/xorg/modules//libxaa.so [0xb79d64b2]
7: /usr/bin/X [0x80d18fc]
8: /usr/bin/X [0x80ded68]
9: /usr/lib/xorg/modules/extensions//libglx.so [0xb7c00b1a]
10: /usr/bin/X(xf86Wakeup+0x3bd) [0x80cacad]
11: /usr/bin/X(WakeupHandler+0x59) [0x8093269]
12: /usr/bin/X(WaitForSomething+0x1ae) [0x81bc89e]
13: /usr/bin/X(Dispatch+0x8d) [0x808f35d]
14: /usr/bin/X(main+0x495) [0x8076f05]
15: /lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe0) [0xb7d2c050]
16: /usr/bin/X(FontFileCompleteXLFD+0x1e1) [0x8076241]

Fatal server error:
Caught signal 11. Server aborting

(II) AIGLX: Suspending AIGLX clients for VT switch
(II) intel(0): xf86UnbindGARTMemory: unbind key 0
(II) intel(0): xf86UnbindGARTMemory: unbind key 1
(II) intel(0): xf86UnbindGARTMemory: unbind key 2
(II) intel(0): xf86UnbindGARTMemory: unbind key 3
(II) intel(0): xf86UnbindGARTMemory: unbind key 4

Do you have compiz enabled? Have you tried it without?