My laptop just had this same hang. syslog says:
Jan 4 18:27:36 i5lap kernel: [ 9525.635064] NVRM: Xid (0000:01:00): 13, 0004 00000000 00008597 00001b0c 1000f010 00000040 Xorg.0.log says [ 9544.565] (WW) NVIDIA(0): WAIT (2, 6, 0x8000, 0x000009f0, 0x00003570) [ 9551.272] [mi] EQ overflowing. The server is probably stuck in an infinite loop. [ 9551.272] Backtrace: [ 9551.326] 0: /usr/bin/X (xorg_backtrace+0x37) [0x80a66f7] [ 9551.326] 1: /usr/bin/X (mieqEnqueue+0x1d1) [0x80a06b1] [ 9551.326] 2: /usr/bin/X (xf86PostMotionEventM+0xb0) [0x80c7e60] [ 9551.326] 3: /usr/lib/xorg/modules/input/evdev_drv.so (0x221000+0x35ed) [0x2245ed] [ 9551.327] 4: /usr/lib/xorg/modules/input/evdev_drv.so (0x221000+0x531d) [0x22631d] [ 9551.327] 5: /usr/lib/xorg/modules/input/evdev_drv.so (0x221000+0x5b85) [0x226b85] [ 9551.327] 6: /usr/bin/X (0x8048000+0x6cb81) [0x80b4b81] [ 9551.327] 7: /usr/bin/X (0x8048000+0x12d2a2) [0x81752a2] [ 9551.327] 8: (vdso) (__kernel_sigreturn+0x0) [0x4f1400] [ 9551.327] 9: /usr/lib/i386-linux-gnu/xorg/extra-modules/nvidia_drv.so (0x12d8000+0x5b8d2) [0x13338d2] It locked X hard. I can still log in over the network. I'll try using apport, but for the moment, here are some basic info: Linux i5lap 3.0.0-14-generic #23-Ubuntu SMP Mon Nov 21 20:34:47 UTC 2011 i686 i686 i386 GNU/Linux Ubuntu 11.10 \n \l nvidia-current 280.13-0ubuntu6 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/792278 Title: Often xorg freezes with EQ overflowing To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers/+bug/792278/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs