I've never really had this problem before, and I don't really think it relates to upgrading to a dual processor system, but I just installed Premiere 5.1c...I tried to export a movie and the video and audio ended up being asynch in the final movie, even though the movie is perfectly synched when previewing. All the timebases and frame rates are the same for the project settings and when exporting, so I don't know what I'm doing wrong...BTW, I am simply trying to replace the sound in an MJPEG clip... Any help would be greatly appreciated.