Run system-config-display ( this will generate a xorg.conf which is still supported by xorg ) , you may need to install system-config-display
http://forums.fedoraforum.org/showthread.php?t=203572
some personal notes on computers especially linux tips
Run system-config-display ( this will generate a xorg.conf which is still supported by xorg ) , you may need to install system-config-display