interlace artifacts after Video Capture

I'm finally getting around to digitizing all my old VHS stuff but I'm running into an issue with interlacing artifacts after I import of FCP7 or uprez in Compressor.

At first I tried to Log and Capture in FCP7 but had some problems getting a signal. I ended up capturing to Blackmagic Media Express because I have a Studio 2 Decklink card. I captured to ProRes with the same settings at the VHS source. When I play back captured clips in the BM Media Express player it looks great. No interlacing artifacts at all.

But when I import to FCP7 and playback; there are interlace artifacts all over the place.

I'm not sure what the problem is. The field dominance seems consistent.

I will confess I don't have a lot of experience working with interlaced footage so it's very likely I might be missing something very basic.

Update: I've found going frame by frame the pattern goes like this: 3 clean frames, 2 frames with horizontal lines on edges in the image, repeat: During playback the interlacing is very noticeable too - but as I said, not at all in Media Experss.

Thanks for any help!