After just installing Fedora 7 on a new drive I was setting the screen resolution to 1600 x 1200. The screen went black with a gray box voting around that reads:

Not Optimum Mode

Recommended Mode: 1600 x 1200

I'm sure this is because I didn't install the driver for this monitor but I don't know how to get to a lower resolution. I tried searching the Fedora 7 installation forum archives but I don't have permission.