Hauppauge 1950 live recording with Xbox

Hey guys! I recently bought the Hauppauge 1950 WinTV because my friends and I wanted to have fun posting some gameplays on youtube. I'm able to record my gameplays in theater mode in Black Ops, but I can't figure out how I can play on my TV while recording. I tried having my Xbox go through a DVD player, than into the WinTV, than to the TV via S-Video cable but I was unable to a picture from my Xbox. Does anybody have a set up that would make it possible for me to record through the WinTV while playing on my xbox? It would be greatly appreciated if you do!! Hoping this is in the right section also.

Thanks!

YouTube - Black Ops: Dual gameplay with Dual Skorpions
Our first video. I was actually surprised at how well the quality turned out.