With 12.10 I can confirm the multi monitor setup problem.
With 13.04 (3.8.0-12 generic) this problem also occurs also without using a second monitor. Ctrl+Alt+F1 doesn't work. Via SSH I can see that Xorg uses up 99% of one CPU core. I don't see any relevant output in X.org.0.log or dmesg.
With 12.10 I can confirm the multi monitor setup problem.
With 13.04 (3.8.0-12 generic) this problem also occurs also without using a second monitor. Ctrl+Alt+F1 doesn't work. Via SSH I can see that Xorg uses up 99% of one CPU core. I don't see any relevant output in X.org.0.log or dmesg.
Keith's workaround `sudo taskset -pa 1 $(pgrep -x Xorg` fixes the issue temporarily.
I'm able to help with further logs or debugging.
lspci -vv: http:// pastebin. com/jmz7mAcE