DVI workstation DIM help

Thanks in advance, I'll be brief.
Dell computer that I have a HDTV (720i) attached to and wanted to get
3D on a antenna building program. I'm a radio operator.

Found a Firegl v3300 card cheap on ebay, got the cables and hooked it
up.

Everything installed fine, however Catalyst will not allow my monitor
to go above 1024x780. No manual (too old I guess).

Tried both outputs, both work. The 2nd monitor has a long list of
resolutions but I cant seem to change to that output.

Do I have to have a 2nd monitor connected? I got higher res with the
on board card.

What is the magic word to make this work like it used to? I've got a
37" monitor that is filled up with just this email.

Thanks,
Onion