I am using Premiere Pro v 7.0. I am working on a 2 hour high school musical that I have broken down into 2 acts of just under an hour each. I exported the first act to an AVI file then converted that to MPEG to make a DVD. When I viewed the DVD I saw that the audio was not in sync in some places. So I went back to the timeline and checked the section and found it was in sync on the time line. So I did a test and exported that same section again, less than 2 mins., and it was out of sync in the AVI. I even tried exporting the video and audio separately, made an MPEG and again out of sync. I have make hundreds of clip reels using Premiere 6.0 and never had this kind of problem.
Self built PC, XFX 7109 motherboard,4gigs of DDR2 667 mhz RAM, Intel Quad Core 2.4 Ghz processor, XFX GeForce 8600 GT video card.