Sounds like SuSe couldn't guess the horizontal and vertical setting of your monitor correctly. In /etc/X11/XF86Config, what do you have under:
#DisplaySize 320 240 # mm
HorizSync 30.0 - 85.0
VertRefresh 50.0 - 120.0
Except of course, with your horizontal and vertical settings, usually if they're not on the back of the monitor you can get them off of the manufacturer's site.
Just one more of the annoyances of X.