Yes, I am putting pultiple m4v files in the same timline, with one ac3 file for the audio to get around the null info that is added to ac3 files that throws things out of sync. It worked perfectly when I did it for the first disc. I am almost certain there are no gaps, since Encore doesn't let you have gaps when you are dropping files in, but I will double check. I didn't see any when I was adjusting the chapter marks.
What is happening is the sound eventually falls behind of the video by a few frames (to about 10 frames near the end of the movie). The movie is one hour and 49 minutes. If the video files are 29.97fps, and somehow the Encore project setting is 30fps, would that cause my issue, or would it cause the audio to get ahead?
I've done the one long m4v file before, but scrubbing through and adding the chapter marks was incredibly annoying.