Yeah, this is happening to me too. I had an a four-year old system that I upgraded to Vista back in February, and this happened to any DVD I tried to create using Windows DVD Maker. About a month ago, I purchased a brand new, high-end system with Vista, and attempted to make the same DVD, with the same result.
Basically, I connect my camcorder via Firewire to my system, and whether I choose to have it automatically import the whole tape and burn it to a DVD, or if I open Windows DVD Maker and attempt to burn the imported movie to DVD manually, the same thing happens - the audio is slightly out of sync with the video.
So that's two entirely different systems, different hardware, same exact issue. I can't imagine that we're the only two people on earth who are experiencing this issue. I'll post back to this thread if I discover anything new about it.