analog video camera as webcam, help please

I have read alot of people use their analog video camera as a webcam. So I pulled out my old 8mm, pluged it into my capture card and it works. Here is the problem. So I fire up msn messenger 7.5.0311 Run the audio/video setup wizard, you know how it works, sound test, microphone test, camera test. I pass all 3. I see a very clear smooth video from my anolog video camera. Says click finish and wa'la your done.So I thought. Now I try to start a video conversation in msn messenger,loads like its gonna work, then in the screen area puts a picture of a webcam with a red x on it.Is there a work around for this or a free program to make it work? Is there a certain WMD I need ?