Artifacts in captured video using AVio HD

I am using AVio HD to capture video signal.
Occasionally the incoming frame has a strange artifacts in it, as if the upper fifth of the frame contains a copy of another frame scaled down by Y-axis.
The problem occurs with various video capturing utilities (AmCap, VLC, etc.)
I am attaching the screen shots of a good and of a bad frame.

Is there a known issue or a workaround for such a problem?
Thanks!!

bad_frame|625x500

This sounds similar to the issue I had in this thread: https://www.epiphan.com/forum/t/av-io-hd-video-artifacts-tearing/966/9