trouble with my monitor display

[m-prime]

Hi,

I recently got my new computer, and i got a probleme.

i got a Viewsonic VP171B (17" screen lcd) with a 1280x1080 native resolution.

If i go higher than 1024x768 the screen go black and a msg says No signal ...

i got 2 4580 in crossfire lastest driver from ati ...

Anyone got any sugestion ?

Thank you.

 

[fowang]

what i can think of is that your screen refresh rate may be out of the reange of the monitor when you are changing screen ress, lower it to 60 and try it see if that works