Dell 1901fp monitor rotation problem

[shilton]

I cant seem to figure out how to completely rotate my monitor(so all of windows xp is rotated, not just MAME). My video card supports rotation but I get a message that says:

 "The requested rotation mode is not supported by your current display mode(resolution, and/or refresh rate, and/or color depth) please change the display mode."

Even though we had tested our exact settings on another pc and it worked fine(it has a different video card, with the dell monitor). Can anyone tell us what is the problem? We have tried for days and cant get it to work. Information on PC we need monitor to work on is below.


System Info:
Petium 3 processor
Radeon 7500 graphics card
512 mb RAM
Dell 19" 1901fp LCD monitor

Monitor Settings(on current pc and other pc):
1024x768(it becomes 768x1024 when flipped)
32 bit color
60 hertz

Can anybody please provide a solution to our problem?