Help with video catpure with Matrox Marvel G200

[Kwad Guy]

I am trying to do video capture with a Matrox Marvel
G200 video card...The configuration:

Windows 2000
Latest G200 video drivers
Beta 2.00 version of Matrox video tools (last version that
support MJPEG compressed capture under Win2K)
Video input: From a VCR.
Program run to effect capture: Video Dub 1.4

The beginning of the tape I'm trying to capture has
some problems...If I start capturing the video, I get
a bunch of dropped frames in the first 7-8 minutes.
After that, the dropped frame rate drops to essentially
0.

Anyway, if I start capture at the beginning of the tape,
after a few minutes the capture stops. Video Dub continues
to run, but no new frames are saved...The problem is
reproducable, although it seems kind of random exactly
where the capture will stop.

If I start capture after the first 7-8 minutes of video,
then capture continues until I stop it. No problems...

Can anyone explain this? Is there something in the Matrox
driver that tells the card that if the input signal is
crappy then stop capturing? It's not Video Dub that's
stopping the capture...I find the same problem (or worse)
if I try to capture using Ulead Media Studio 6...

Kwad