I googled this and found some threads about it occurring in previous versions of iDVD. But not much about it in iDVD6. I'm currently experiencing this problem. When I Save to Disc Image, after encoding is done I get a message saying there was an error during burning, then another message comes up saying there was a multiplexing error. I've tried 3 different times. Here is my project info. 110 minutes, using Theme 6.0 Shelves. Title has 3 jpegs and a 1 minute song with a Play and Chapter button. There are 4 chapter pages of 6 chapters on each. Each chapter page is set to a 30 second loop with Movie buttons and a song. Here is the gist of the problem. I save to disc image and when it finishes I get the error messages mentioned above. The first 2 times I tried burning to DVD using Disk Utility. The DVDs were successfully burned but both failed Verification at 98%. When played in a DVD player on my TV the DVDs work but the final 2-3 chapters are real sketchy, showing scenes from other chapters and garbled voice-overs that sound like aliens fornicating. The final chapter just freezes and sends me back to the Menu. On my computer using the DVD Player App those chapters crash the player and I get a message saying the disc is scratched (even when playing from a disc image...) Here is what I've done to try and fix the problem. Repaired Permissions, checked the original project in iMovie, re-did the chapters, re-shared from iMovie to iDVD each of the 3 times I've tried to encode it. Has anyone else had this problem when dealing with iDVD6? How did you get past it? Currently I am encoding a smaller TEST dvdproject to see if that works. I may try cutting back chapters and also I may try encoding the project completely on my internal HD rather than my external FW HD....although I never had problems like this before when working from my external. What else can I do? EDIT: The small TEST dvdproject saved to disc image with no errors...going to try encoding my project on the internal HD now. EDIT2: WOW, I transferred my dvdproject to my internal and chose to Save as Disc Image. It encoded and made the image in less than 2 hours, whereas on my external HD(FW) it was taking nearly 8 hours! Also, the multiplexing error did not show up and upon playing the .img in DVD player everything appears to be in working order. One other change I did make to my project before attempting the encode on the internal was I removed all the transitions (Push) from the Chapters...I hate to think that that was the problem so I'm going to put the dvdproject back on the external and Save it as a disc image on the external...see if the error crops up again. Well, it seems I solved my own problem, so I hope this can maybe at least help someone else who had this problem. I'll post back regarding encoding again on the external.