Olie,
I'm not sure what happened to my previous thread, but it's gone for some reason. I hope it's nothing personal.
Anyway, I did some more testing with the Blackmagic card with both beta 14 and 16. Here are the results:
Beta 14
Primary Monitor 50% - Normal amount of interlacing
Primary Monitor Fullscreen - Almost perfect - just a slight bit of interlacing
Secondary Monitor 50% & Fullscreen - Normal amount of interlacing (on both my projector and an LCD monitor)
Beta 16
Primary Monitor 50% and Fullscreen - Normal amount of interlacing
Secondary Monitor 50% and Fullscreen - Extreme amount of interlacing (wavy) at 1024 x 768 (on both projector and LCD monitor), but normal interlacing at 1280 x 1024 (on monitor only)
My projector's native resolution is 1024 x 768 so I always set it at that. The LCD monitor's native resolutions was 1280 x 1024.
That's what I found - hope it helps you out.