Vegas and the client's video really threw me for a six.
The thumbnails looked totally different to what I was seeing in the preview monitor. I changed the preview from Best to Preview and bingo, they looked the same.
Ha, of course. This is a very early video from the days when Digital Video Electronics did all manner of wierd things. Like only process one field. This was a composite of two images and one of the original images was only in one field and the other image in the other field. So pick one field and you see a full body shot of a woman, pick the other and you see a close up of a man's face.

Bob.