CTRL ALT BACKSPACE

CTRL-ALT-BACKSPACE to restart X Windows in Ubuntu 10.10

Recently I started to have a problem with my new 22" flat panel where it won't wake up from sleep - leaving me with just my laptops display running.  Pulling the HDMI plug and re-inserting it works in Windows 7, but not in Ubuntu - I get a popup message stating that the discovered monitor cannot be enabled as the new display configuration doesn't fit - or words to that effect.