After creating a project in iDVD, the option to burn the DVD is not available. The Burn button does not respond when you click it.
Solution
Copy the iDVD project and any files associated with it (iMovie projects, still photos, and audio files) to a computer that has a built-in SuperDrive.
Starting with version 3.0.1, iDVD can be used on any Macintosh computer with a PowerPC G4 or G5 processor to create DVD content. However, the option to burn the finished DVD is only available on computers with a built-in SuperDrive. iDVD 3 may be included with your computer, even if it does not have a SuperDrive.