I tried to start Empathy, and X crashed with the following backtrace. I can't reproduce, and addr2line is not coöperating with me today (it feeds back “??:0” for every address I try, even having pointed it at /usr/lib/debug/usr/bin/Xorg et al) so I apologise for the lack of details.

[    38.205] 
X.Org X Server 1.12.1.902 (1.12.2 RC 2)
Release Date: 2012-05-19
[    38.205] X Protocol Version 11, Revision 0
[    38.205] Build Operating System: Linux 3.2.0-2-amd64 x86_64 Debian
[    38.205] Current Operating System: Linux queeg 3.2.0-3-amd64 #1 SMP Thu Jun 28 09:07:26 UTC 2012 x86_64
[    38.205] Kernel command line: BOOT_IMAGE=/vmlinuz-3.2.0-3-amd64 root=/dev/mapper/queeg160-root ro quiet i915.modeset=1
[    38.205] Build Date: 20 May 2012  08:57:17AM
[    38.205] xorg-server 2:1.12.1.902-1 (Cyril Brulebois <kibi@debian.org>) 
[    38.206] Current version of pixman: 0.26.0
[    38.206] 	Before reporting problems, check http://wiki.x.org
	to make sure that you have the latest version.
[  2627.932] 
[  2627.933] Backtrace:
[  2627.934] 0: /usr/bin/Xorg (xorg_backtrace+0x36) [0x7feba5715796]
[  2627.934] 1: /usr/bin/Xorg (0x7feba5597000+0x1822b9) [0x7feba57192b9]
[  2627.934] 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7feba46be000+0xf030) [0x7feba46cd030]
[  2627.934] 3: /usr/lib/xorg/modules/extensions/libglx.so (0x7feba1e30000+0x45284) [0x7feba1e75284]
[  2627.934] 4: /usr/lib/xorg/modules/extensions/libdri2.so (0x7feba160a000+0x1afc) [0x7feba160bafc]
[  2627.934] 5: /usr/lib/xorg/modules/extensions/libdri2.so (0x7feba160a000+0x1b58) [0x7feba160bb58]
[  2627.934] 6: /usr/bin/Xorg (TraverseTree+0x29) [0x7feba5611ae9]
[  2627.934] 7: /usr/lib/xorg/modules/extensions/libdri2.so (DRI2SwapBuffers+0x17a) [0x7feba160cbda]
[  2627.935] 8: /usr/lib/xorg/modules/extensions/libdri2.so (0x7feba160a000+0x3e72) [0x7feba160de72]
[  2627.935] 9: /usr/bin/Xorg (0x7feba5597000+0x52e41) [0x7feba55e9e41]
[  2627.935] 10: /usr/bin/Xorg (0x7feba5597000+0x41ed5) [0x7feba55d8ed5]
[  2627.935] 11: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xfd) [0x7feba33e8ead]
[  2627.935] 12: /usr/bin/Xorg (0x7feba5597000+0x421ad) [0x7feba55d91ad]
[  2627.935] 
[  2627.935] Segmentation fault at address 0x28968f27f03c