Computer to HDTV issues...

Hello,


I have hooked my computer up to my 55" SONY WEGA HDTV through the HDMI port. I am having trouble finding a resolution that will enable the desktop to fit the entire screen. On the left, right and top there is a black bar that surround the desktop; it also isn't completely centered. I read my manual and it stated that the TVs resolution is 1280x720. It runs all the way through 1080i. I have tried underscan, overscan, and native, and I cannot find a resolution that will evenly fit my screen.


I am running a 7800GT.


Any custom resolutions I should try?


Thanks