I just upgraded my Mythbuntu (xfce desktop) 11.04 system to 11.10 and after I rebooted the desktop doesn't appear. XWindows seems to start but I get nothing but a blank screen. Once after a reboot I saw the X-cursor but I don't know how to go about fixing anything. Should I switch to a terminal and try to get networking working? Is there a way to revert to 11.04 from the terminal?