I assume from what you say that you are adding multiple m2vs to one timeline?
What is your process for adding them?
Or the import alone fails before you add any?
What are the export settings from PR?
One timeline, one AC3 file, and 14 m2vs.
MPEG2-DVD (Video only)
Bitrate: VBR, 2 pass
GOP M Frames:3
GOP N Frames 12
Video is about 4GB, Audio is about .5GB.
Can you try exporting your project to a different format? I've had issues with .m2v and ac3 for fairly large file sizes - anything bigger than 2 gigs.
Does Premiere allow you to export to .m2ts? If so, give that a shot.
I am having the same problem however, I can't even open Encore without it crashing (not responding) and I am on a MAC.
I'm don't think that is the "same problem," unless you are mixing one ac3 with multiple m2vs on the same timeline. (If the following doesn't solve your issue, start a new thread.)
In any event, the following may not be directly applicable to your OS or situation, but includes global issues and specifics. Look in particular at numbers 1 and 4.
Troubleshoot system errors and freezes | Adobe software on Mac OS 10.x
Edit: Reading my mind? I'll add this to your new thread!