Laptop Monitor Not Usable By GUI

I just made my laptop dual boot with Win XP (original) & RH 7.2. I can login to RH fine and get a command line. When I type “startx” I get an error saying RH has found my screen but it has no usable configuration. I ran Xconfigurator to manually set up my monitor but nothing works. RH finds my video card fine (ATI Rage Mobility) and I can set everything up correctly as far as my video card ram, screen verticle and horizontal refresh etc. Any input would be appreciated. (I’m extremely green to RH so be detailed)

Thanks,
Ben