For all you lossless AVIheads out there, I have been using Lagarith for some time for my VHS transfers and other lossless work in MEP. Recently I was using VDub to do some filtering, and exporting that in LAGS to MEP as an AVI. I noticed a bit of frame-jumping/splitting and general pork-chop performance, so I tried HUFF; same result. I then remembered I did a project last year where I had all sorts of trouble with a short LAGS AVI that I had created for the end of a slide show (created in MEP and then brought back into the project).

In desperation, I tried MagicYUV, and it was as smooth as silk. So I bought it (US$15).

If you're having issues with AVIs exported from VDub or MEP, try MagicYUV. There is a trial.