Ah, yes i have seen this before. It is actually a huffyuv codec bug and always seems to be original layer specific usually the result of the initial encode from MPEG" to avi . This also happens in Adobe premier. I originally used this codec and this would happen when rendering in premier. It would randomly happen and never usually the same frame twice. I switched to the lagarith lossless codec and the problem disappeared. And it never showed up in any media player either, but it isn't a bug within vegas.

one thing that may be relevant though. did you encode the mpeg files to huffyuv using virtualdub? i just tried some footage that i had problems with in after effects but this time using DVD2AVI and the problem has disappeared, so i'm now wondering if its a bug with virtualdub.

Also i noticed something in the clip. the first lightsaber shot. Did you use my clip for that shot and overlayed your saber over the top of it?