Did you install all the drivers? More at link.
See Step 4 of chapter 6 at http://manuals.info.apple.com/en_US/Boot_Camp_Install-Setup_10.6.pdf
I have a problem with my Samsung LE32R41BD tv. I am running my bootcamped Macbook pro into it via HDMI. When I run it in Mac os the screen resolution is perfect and everything fits onto the screen perfectly. However when I run it in windows 7, I can't find for the life of me how to get everything to fit perfectly on the screen. Thank you very much if anyone could help.