The some is happened to me, only way to boot is to remove xorg.conf, anyway it's the same with 173 and 177 nvidia driver.
-- Ubuntu freezes right after login with nvidia drivers https://bugs.launchpad.net/bugs/326368 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs