I wanted to add that Womble, also known as MPEG2VCR (
http://www.womble.com) has an option in remuxing where you can move the sound forwards or backwards. It can fix a lot of problems. I used it last night to fix a terrible sync problem with my recording of Futurama. I have digital cable and sometimes the signal gets messed up and that happened last night. My sound was off by over a second, but I was able to get it fixed with Womble's help.