Problem getting my recording set up to stream on my computer.

I have a Dazzle DV 170 capture card, and I can record in standard definition form my xbox using the standard dazzle software. The only problem is, when i try to stream onto a website like ustream, or any site for that matter, the site doesn't pick up my capture card as a valid camera. I have an acer computer with windows xp sp 2. Any help is greatly appreciated.