I think Knoppix loads with default resolution of 1280 and a high refresh frequency I dont know the exact values but, if u hit F2 when the Knoppix boot screen comes it shows the values I think.

U might have to set screen resolution and hsync and vsync using

Code:
knoppix screen=<ur resolution> vsync=<supported freq at this res> hsync=<supported freq>
U would have to get that info abt ur monitor. That solved my problem of monitor turning off after configuration.