I don't know about you but I had a hell of a time getting X to work right on my Dell Latitude CPT c. Its only a 333mhz, 128MB of RAM but I finally got it to work with RedHat 7.0, after trying 6.0, 6.2 and a few other Distro's. Anyways, my problem was it was freakin 320x280 and it wouldn't change. It was so large, the Icons were about half the size of the screen itself. 7.0 seem to have cured my problem though.
Oh, mine has a Neomagic card, but the screen I have yet to find out, I just used a Dell Super VGA color in the monitor list.