wide screen display

I have a Laptop Acer ASPIRE 5740G with ATI HD5470 graphic card.
The display is a wide screen and has a resolution of 768x1366.
OS: opensuse 11.2

Sax has only 768x1024. I can choose the correct resolution.
Text display is no problem but cad is not possible. X and y are not the same length!
How can I change the resolution?
I found at my yast2 no longer sax. but I can start sax from the root command line.

Install the driver
Read this first

openSUSE Graphic Card Practical Theory Guide for Users - openSUSE Forums