Its happens randomly with me too on 32bit Ubuntu 12.04 ThinkPad R500 with Intel 4500MHD video card
Xorg.0.log: Backtrace: 0: /usr/bin/X (xorg_backtrace+0x37) [0xb76b8647] 1: /usr/bin/X (0xb7530000+0x18c3ca) [0xb76bc3ca] 2: (vdso) (__kernel_rt_sigreturn+0x0) [0xb750d40c] 3: /usr/lib/i386-linux-gnu/libpciaccess.so.0 (pci_device_next+0x100) [0xb7453170] 4: /usr/lib/i386-linux-gnu/libpciaccess.so.0 (pci_device_find_by_slot+0x4b) [0xb745322b] 5: /usr/lib/i386-linux-gnu/libpciaccess.so.0 (pci_device_vgaarb_init+0xf0) [0xb7455780] 6: /usr/bin/X (0xb7530000+0x81474) [0xb75b1474] 7: /usr/bin/X (xf86BusConfig+0xc1) [0xb759fbf1] 8: /usr/bin/X (InitOutput+0x7ca) [0xb75acc2a] 9: /usr/bin/X (0xb7530000+0x251a0) [0xb75551a0] 10: /lib/i386-linux-gnu/libc.so.6 (__libc_start_main+0xf3) [0xb71904d3] 11: /usr/bin/X (0xb7530000+0x25699) [0xb7555699] Segmentation fault at address (nil) Caught signal 11 (Segmentation fault). Server aborting -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/740785 Title: Caught signal 11 (Segmentation fault). Server aborting To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/740785/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
