ATI Hdtv Adaptor?

I've read every FAQ on Ati's site, every post dealing with HDTV
adaptors on AVS forums.. and I still can't get anywhere with using my
AIW9600xt on a Panasonic 47" HDTV.

My problem is the scan width, ATI has several pages detailing Custom
Scan Preferences and setting them. I can go through displays, advanced,
settings, adjustments and get to the Add Remove custom scan settings,
but the ADD/Remove buttons are always ghosted out and not active.

Any suggestions would be appreciated.

I'm using the Latest ATI grafix drivers dated Fab. 12 /2005


Help, Please.