only not quite as bad, but still noticeable especially under stage lighting. Hadn't noticed them in the past. Strikes me as some sort of interlacing problem.
Yeah, it's interlacing, but it's perfectly normal. If you are editing for output to tape or DVD for viewing on a television, leave it alone. If you are creating output for viewing on a PC monitor, then you will need to de-interlace.
It seems that deinterlacing is turned on by default in VV4. I always used default settings in VV3 and never questioned them. Do you think I should turn deinterlacing off in the settings or did SF have a reason for this?
FWIW, I think if you import an interlaced clip, have your proj set to interlaced, and render interlaced, you'll get interlaced output. Same goes for progressive - the settings in VV4c are more to tailor the method if I understand it correctly, though the inclusion of off is confusing.
As John mentioned, rendering interlaced or not depends on your final destination. If I recall you go from DVD to VHS tape, which means TV, which likes interlaced.