The best way I know of installing the ATI drivers is to do it manually...
-Go to the directory where you downloaded the rpm file
-Open a terminal and type rpm2tgz <packagename.rpm>
-Extract the .tgz
-Move all the files to the named directory
-Run make.sh and make_install.sh
-Run fglrxconfig
Thats worked the best for me, worked every time so far. Good Luck!