It's possible that your source MPEG-2 contains an irregular pattern of pulldown flags, instead of a constant 3:2 pulldown. You could try honouring the pulldown flags in the video stream; I'm not sure how this would be done in Vegas, but this would mean editing in 30i (29.97fps).
It's possible that your source MPEG-2 contains an irregular pattern of pulldown flags, instead of a constant 3:2 pulldown. You could try honouring the pulldown flags in the video stream; I'm not sure how this would be done in Vegas, but this would mean editing in 30i (29.97fps).