I need help with PC on LCD TV

Okay, here's what's happening...


I just got a Westinghouse 27" 27w7 LCD TV.


Main use is for living room TV and secondary use will be for my PC, which I plan to browse the net, play games, play DVDs through the PC, etc.


My problem is that while running my PC to the LCD works great while using VGA, when I use DVI/HDMI I get a very strange image. The text seems somewhat garbaled and the color seem really saturated.


The native resolution on the TV is 1366x768 (is this normal? why not 1280x720?) and when running VGA at native resolution I get a great 1:1 pixel image... I can also run 1280x720 with VGA and it looks fine, just not as clear as running native.


Running any reolsution, including the seemingly supported 1280x720 with HDMI seems to just look messy... garbaled and strange.


I'm using a pretty cheap DVI -> HDMI cable I got at radio shack... could this be related to the problem?


Could it be my video card?


My TV?


Software?


I'm not sure what else to try, I really want to get this to look good on HDMI because it's a better image if it works... that and I use the PC for DVDs and the TV also doesn't support PIP if I use VGA instead of HDMI.



What would cause the HDMI image to look so crappy?


Any advice is greatly appreciated...


Thanks.