My guess is that compiz, while checking if it is possible to run on your card (which it probably is not), makes X crash.
The XorgLogOld.txt shows that the X server crashed: Backtrace: [ 213.011] 0: /usr/bin/X (xorg_backtrace+0x3b) [0x80ef31b] [ 213.011] 1: /usr/bin/X (0x8048000+0x5d00d) [0x80a500d] [ 213.024] 2: (vdso) (__kernel_rt_sigreturn+0x0) [0xc6c40c] [ 213.024] 3: /usr/bin/X (FreeClientResources+0xed) [0x80655ad] [ 213.024] 4: /usr/bin/X (FreeAllResources+0x60) [0x8065680] [ 213.024] 5: /usr/bin/X (0x8048000+0x1a606) [0x8062606] [ 213.025] 6: /lib/libc.so.6 (__libc_start_main+0xe7) [0x133ce7] [ 213.025] 7: /usr/bin/X (0x8048000+0x1a1b1) [0x80621b1] [ 213.025] Segmentation fault at address 0x4 [ 213.025] Caught signal 11 (Segmentation fault). Server aborting [ 213.025] Does it crash if you run "glxinfo"? It would help if you can provide information as explained on https://wiki.ubuntu.com/X/Backtracing at least installing the -dbg packages and attaching the new Xorg.0.log.old after restarting and reproducing the crash. ** Changed in: xserver-xorg-video-mga (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-mga in ubuntu. https://bugs.launchpad.net/bugs/723747 Title: Cant login to desktop _______________________________________________ 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
