Screen update freq. resets every time I restart my computer

I Have just installed OpenSUSE 11.0 on my IMB Thinkpad T40. Every time I reboot it the update frequency resets. This means that every time I start the computer the “Desktop area” is much bigger than the actual display, and I have to scroll around to find my desktop icons etc.

If I change the frequency from 38Hz to 50Hz the desktop area fits the screen.

Any body knows how to fix this problem?