I had a similar problem. I was trying to run Knoppix in failsafe. After a certain point the monitor kept going from "Power saving will be enabled" to a black screen, and back every split second. This repeated forever even when the system showed no sign of activity. Unfortunatly unless you are trying to run in failsafe I can not help you. The problem I had was a multiprocessor problem, which knoppix nosmp fixed. This was on a standard VGA monitor though.