Audio synchro Issue When Outputing

[dellsam34]

I have some few gigabites .trp video files recorded with sat receiver, when I load and edit comercials the output file will be out of synchro with its audio, the funny thing it happens with certin edited segments not all of them, I will not send sample because it doesn't happen on small files, only when the segments are long enough to accumulate the audio delay.