audio sync help

[defsrg]

i know this topic has been probaly beaten to death but after a through search i cannot find the answer to my problem. i have 4 mpegs i had to download via a p2p connection as i was missing them from completing a full season, they play find on my pc but when authored and burned they lose audio sync about 5 minutes in. i have tried this using both tmpegenc dvd author and dvd lab. i have tried demultiplexing and then multiplexing them back again. now i have been fortunate enough not to have any audio sync issues with anyhting i have done extracting from my directivo (knock on wood) so this is a new thing to me. my thought is probaly due to the fact the mpeg i downloaded is at 44100 hz and both tmpegenc and dvd lab both require them to be at 48000hz to be dvd compliant i feel maybe this is where my sync issues are coming into play. i am still exploring the tmpgenc dvd author program itself so i just noticed the the program automatically defaulted to rencode the audio at a birate of 224kbps,48000 hz. all my extracted dtivo "mpegs " are at 192kbps,48000 hz. just an educated guess on my part like i said this is a new probelm to me. if anyone has some experience with this pleae let me know and thanx for all ahead of time
ps also would it be better to reencode at linear pcm rather than mpeg - 1 audio layer 2???