Problems with 12.04.2 LTS. I've reinstalled 3 time on different dell hardware (laptops). When system screen locks I can't get back to x, ssh sessions won't work either. I can get to tty and have a login screen, but each time I try to put a user in I don't get an opportunity to put a password in, just goes back to login? It seems the only way I can get out of this state is to power down the system which reboots into a kernal panic and all is dead and requires a reboot.

Any suggestions on how I can safety reboot of get something out of one of the tty?