I don't know exactly what you mean by sweetspot drivers. I probably have them somewhere but I didn't actually install the card so I wouldn't know where to find them and what to look for. I'm totally annoyed about the image shift issue though. I mean, how could no one know on video help? (almost 100 views, no replies)
It's good that you discovered a way around it but that does seem weird that pressing stop would make a difference. Maybe the heads somehow can't hit the same field each time.
However, I actually did encounter that example of a interlaced cut but it wasn't quite exactly with video. And I'm pretty sure it will give me the same result at that frame every capture too.
Just for fun here it is.

http://img107.imageshack.us/img107/5232/zelda3ms2.jpg

[URL=http://imageshack.us][/URL]
I must not have paid attention to what it actually looked at full size so I didn't realize I would get a double image.
Would you have any suggestions about where else to ask about the PDI image shift?