Audio and Video start in sync, but then drift

I bought a LiteOn 1107HC1 from BestBuy and have been using Taiyo Yuden 4x and 8x DVD-R media. DVD’s that I burn on the 1107 (via S and audio cables from a TiVo box) play perfectly in the 1107, but don’t play well on other players. On my cousin’s Apex (supercheapo, free from DirecTV) DVD player, and it had no trouble reading the DVD-R’s, however, the longer we watched, the more the audio and video was out-of-sync. I believe that the audio was running a tiny bit faster than the video. I think that every time a new chapter started, they synched back up again, but then drifted away again. On my Toshiba SD-2800, it does the same, but some chapters (if you seek to the chapter) don’t have audio at all. On my Toshiba SD-2300, it simply says “media error” or something like that.

What causes this? Who’s fault is it? LiteOn? Should I take it back and get a more expensive DVD recorder? Is it just a bad unit… should I try another 1107HC1? If I do, I’ll bring media to the store and try it right there. If it drifts, then I can try a different box.

What do you think? This seems a very fundamental problem and I’ve found lots of people posting in many forums with this same problem, but no solid answers. If there are answers at all, they are usually just “bring it back” or “try different media.”

I don’t have that many more days to return it, so please respond quickly.