Apple – Support – Discussions – Multiplexing and burning error …. SDMacuser solves the issue:
Make sure to quit iDvd prior to disposing of the plist. This procedure will not harm your mac nor the app. Lastly I’d like you to Restart your mac and try iDvd one more time. Post back if you need further help.
Niels solution worked for the poster.
The solution for rawsaxy:
Well, after making the mistake of adding permissions to internal files on the main hard drive and system folder, I ended up with the Gray Screen and Restart Loop problem. I was able to backup the important files before doing an Erase & Install. Everything is working better than before now. I left the Mac OS at 10.5.2, and guess what? I was able to burn a DVD in iDVD ’08 now! Thank you Lord!
Another two solutions are from this thread.
1. Try another kind of media
2. Use a Computer CD/DVD cleaning pad.
Both of this solutions fixed the problem for two posters.
Bengt has some great solutions to solve this. Also you should avoid Memorex and try Verbatim. Following his suggestions solved the issues for the poster.