Help---- modes not supported (after monitor change)

Hi

After I changed my samsung 22" LCD to Westinghouse W2613(720p), the trouble happens when I try to boot opensuse(ver10.0).
The grub screen appears but in a mode used by the previous samsung LCD 1280x1040. Vista automatically adapts to the correct mode: 1366x768. (I didn’t adjust anything).
However, if boot into suse, after the initial screen info rolls, the screen goes black and says “Video4: modes not supported”.

I boot “fail and safe”, run init 3
then sax2, but each mode even 800x600 fails the test.
I modified the “xorg.conf” according to someone else’s experience, but still…
the hwinfo --monitor gives nothing. maybe the system cannot find the monitor?

Try running this in su terminal: sax2 -r

Yes it works!
Thanks a lot!
btw, the mainboard screen at boot time & the grub screen are still not in the right resolution. The right resolution is WXGA(1366x768).
What’s the “Kernel VESA mode code” for WXGA? I didn’t find it.