Comment 92 for bug 322202

I think that I am experiencing similar same issue, backtrace in Xorg slightly different but overall the same ;):

(II) AIGLX: Suspending AIGLX clients for VT switch

Backtrace:
0: /usr/bin/X(xorg_backtrace+0x26) [0x4ef246]
1: /usr/bin/X(xf86SigHandler+0x39) [0x476689]
2: /lib/libc.so.6 [0x7fb60c57d190]
3: /usr/lib/libdrm_intel.so.1(drm_intel_bufmgr_check_aperture_space+0x3) [0x7fb60a36c8f3]
4: /usr/lib/xorg/modules/drivers//intel_drv.so(i830_get_aperture_space+0x40) [0x7fb60a5d40f8]
5: /usr/lib/xorg/modules/drivers//intel_drv.so [0x7fb60a5d4ce2]
6: /usr/lib/xorg/modules/drivers//intel_drv.so(uxa_copy_n_to_n+0x18b) [0x7fb60a5e94b7]
7: /usr/lib/xorg/modules//libfb.so(fbCopyRegion+0x19a) [0x7fb609d5659a]
8: /usr/lib/xorg/modules/drivers//intel_drv.so(uxa_copy_window+0x127) [0x7fb60a5ead3f]
9: /usr/bin/X [0x535e7b]
10: /usr/bin/X [0x4dfa8f]
11: /usr/bin/X(compCopyWindow+0xac) [0x4ff5dc]
12: /usr/bin/X(miMoveWindow+0x1f5) [0x4e6d15]
13: /usr/bin/X(compMoveWindow+0xae) [0x4ffbbe]
14: /usr/bin/X(ConfigureWindow+0x576) [0x4392a6]
15: /usr/bin/X(ProcConfigureWindow+0x8d) [0x44c9ed]
16: /usr/bin/X(Dispatch+0x364) [0x44d374]
17: /usr/bin/X(main+0x3bd) [0x43321d]
18: /lib/libc.so.6(__libc_start_main+0xe6) [0x7fb60c5695a6]
19: /usr/bin/X [0x4326a9]

In Debian this bug is
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=529072

X org is 7.4
intel driver 2.7.99.1
kernel 2.6.29-2-amd64