Similar issue for me, 10.04, gdm 2.30.2.is.2.30.0-0ubuntu4, never happened until today, only software change was installing some regular official mainstream updates and tweetdeck app.
Backtrace: 0: /usr/bin/X (xorg_backtrace+0x3b) [0x80e938b] 1: /usr/bin/X (0x8048000+0x61c8d) [0x80a9c8d] 2: (vdso) (__kernel_rt_sigreturn+0x0) [0xd4e410] 3: /usr/bin/X (0x8048000+0x2a1b0) [0x80721b0] 4: /usr/bin/X (0x8048000+0x1ed7a) [0x8066d7a] 5: /lib/tls/i686/cmov/libc.so.6 (__libc_start_main+0xe6) [0x2ccbd6] 6: /usr/bin/X (0x8048000+0x1e961) [0x8066961] Caught signal 3 (Quit). Server aborting ** Attachment added: "xdmerr.log" https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/559039/+attachment/1716737/+files/xdmerr.log -- X Crashes when enabling second monitor https://bugs.launchpad.net/bugs/559039 You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in ubuntu. _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp