When frameserving a DivX+Added subtitle from VirtualDub into TmpgEnc, I noticed a discrepancy between the number of encoded frames (for example, for 'The Shawshank Redemption - 20500 frames) and the number of frames served by VirtualDub TO Tmpef (around 20000)....

VirtualDub clearly stated that it served 98% of the actual amount of frames in the movie-file. (somehow, 2% of the frames were either not served, or not declared as served...)

Did I really lose ~2% of frames? Does that account for jittery motion I sometimes find in the encoded result?