Changing screen res in Redhat 8.0

[shipdadip]

Hi all,

	Using Bluecurve/Gnome in Redhat 8.0.  I have a Dell 8100 and I want to
change the screen res to 1600x1200.  In Gnome u can go to system
settings/display and change it.  When I go there all the resolutions
over 1024x768 are greyed out.  SO I edited my XF86Config file and added
1280x1024 and 1600x1200 and restarted X.  Still coming up in 1024x768
and the options are still greyed out.  Can anyone help?

PS I changed the res in XF86Config where it says "Supported resolutions"
I looked for a setting like "Default Res" or something like that. 
ANyone have any ideas?