Capture DVSD without capturing audio

[cjeAlso]

I have an app using DirectX 9 to capture a dv stream from a camcorder, everything is working well. I now want to write only the video portion of the dv stream to the avi file so I disconnected the audio output pin from the dv splitter - When I capture, I get 1 single frame replicated for the entire duration of the capture. I have also tried connecting the audio pin to the NullRenderer with the same results. The filter graph works find in GraphEdit but not inside of my app

any ideas??
thanks in advance