I hooked up ASUS VH238H monitor to our old computer running SUSE 10.1, but I could not get it to display in 1920 by 1080. I ended up modifying xorg.conf again.
This time, I changed "screen" section. I basically removed all the unnecessary resolutions and left only 1920x1080 in order to force the video card to display in that resolution. This did the trick. I wonder if this would work for the other, even older machine, running redhat.
-unkokusei