project too long

You don't say how long your project is, but it is probably a question of setting the correct encoding:

iDVD encoding settings:

http://docs.info.apple.com/article.html?path=iDVD/7.0/en/11417.html

Short version:

Best Performance is for videos of up to 60 minutes

Best Quality is for videos of up to 120 minutes

Professional Quality is also for up to 120 minutes but even higher quality (and takes much longer)

That was for single-layer DVDs. Double these numbers for dual-layer DVDs.

Professional Quality: The Professional Quality option uses advanced technology to encode your video, resulting in the best quality of video possible on your burned DVD. You can select this option regardless of your project’s duration (up to 2 hours of video for a single-layer disc and 4 hours for a double-layer disc). Because Professional Quality encoding is time-consuming (requiring about twice as much time to encode a project as the High Quality option, for example) choose it only if you are not concerned abo

In both cases the maximum length includes titles, transitions and effects etc. Allow about 15 minutes for these.

You can use the amount of video in your project as a rough determination of which method to choose. If your project has an hour or less of video (for a single-layer disc), choose Best Performance. If it has between 1 and 2 hours of video (for a single-layer disc), choose High Quality. If you want the best possible encoding quality for projects that are up to 2 hours (for a single-layer disc), choose Professional Quality. This option takes about twice as long as the High Quality option, so select it only if time is not an issue for you.

Use the Capacity meter in the Project Info window (choose Project > Project Info) to determine how many minutes of video your project contains.

NOTE: With the Best Performance setting, you can turn background encoding off by choosing Advanced > “Encode in Background.” The checkmark is removed to show it’s no longer selected. Turning off background encoding can help performance if your system seems sluggish.

And whilst checking these settings in iDVD Preferences, make sure that the settings for NTSC/PAL and DV/DV Widescreen are also what you want.

http://support.apple.com/kb/HT1502?viewlocale=en_US

iMovie renders everything in one pass, unlike Final Cut Pro, which renders as you go. (RENDER is what happens when you use the SHARE menu in iMovie.) This means that for long movies, it takes a very powerful computer in iMovie, and not quite as powerful for FCP.

If you are making a feature length movie, (or depending on the specs of your Mac, anything much over an hour), then I would go to Final Cut Pro.

Or you could split your project into 2 or more smaller projects in iMovie.

To do this, select your Project in the Project Library List. Right Click on it and select DUPLICATE PROJECT.

Do this again. Rename these new projects as your project name Part 1 and Part 2. (Keep the original intact just in case something goes wrong.

Now you can SHARE these parts and it will be half as long.