[whych]

knet_nn
Make sure that your monitor is directly connected to the pc - ie it doesn't have any keyboard, video, mouse switch in the loop.
Boot to run level 3
login as root and run /usr/bin/aticonfig --initial.
Next configure sax by typing: sax2 -r -m 0=fglrx
(The 0 is number zero not a letter)

Once you have monitor configured, exit sax and type startx to get the xServer running.
If everything is fine, reboot and login as usual.

If you are still having problems, use yast in level 3 to remove the ati repo driver and download and install the ati driver from their site.
Do the automated install in run level 3. Make sure you have first downloaded the latest kernel development for your kernel (also from yast.)