I watched it a home, where I know I have no connection issues, and saw what you were talking about. Is it really 20s for you though? For me it's maybe a couple. I went back to look at the 2nd episode and it was off by about 1 as well. I totally forgot to go back and look at the 1st one, because that one was actually cut up into 3 parts, so I wonder if it's fine.
Vimeo only allows a small amount of upload per week, so I have to encode the files to be pretty small. Strange about the wma(wmv?) requirement, since mp4 is largely becoming the standard. There is room to make mine slightly better quality if that is the cause of sync issues. I'll try to remember to actually watch it after I convert mine and see if the sync issues are present before they are uploaded. If they are fine, I'll either try breaking them up again, or see if there is a wmv conversion option without making it a 2nd step.