Here's a shot in the dark.
Take a look at
/etc/X11/XF86Config. (It's there on Slackware; it might be elsewhere on Fedora.) You probably have something like:
Code:
Subsection "Display"
Depth 16
Modes "1024x768"
EndSubsection
Change that to "1280x1024", and you should be all set.
In fact, mine is this:
Code:
Subsection "Display"
Depth 16
Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubsection
I do this so that if I want to take a closer look at something on the screen, I do a <Ctrl><Alt><keypad-plus> to zoom in progressively, and <Ctrl><Alt><keypad-minus> to zoom out. It circulates, so if you're at 1280x1024 and do a <Ctrl><Alt><keypad-minus>, you'll go immediately to the most extreme zoom.
At least it works that way for me.
Hope this helps.