How Do?

i've got an xvid ac3 file which plays fine in its original form but not when i encoded in mpg. i have tried CCE Tmpgenc and Nero to encode it but the problme is always the same... audio is fine at the start and at the same point it every time it suddenly lags quite dramatically.

i read chicken mans guide to manipulating mpg sounds but he only covered problems where the sound gradually goes out of synch of is totally out of synch all the way through.

is their anyway i can correct the mpg file?

it appears that there is a couple of bad frames in the mpeg 2 file. virtual dub won't load the file, is there another program a can use to edit out the bad frames? as i said the original avi file plays purfect and every time i re-encode i get the same error

can anybody help?