REMEMBER — DVDs are HIGHLY compressed forms of video delivery!!! Uncompressed video won’t play on a DVD.
Not sure you are going to be able to get 100 minutes on iDVD… I believe it has a set compression formula that will do 90 minutes max. HOWEVER… since you are in 24fps (not what you actually SAID… but I’m assuming) it might think the number of frames will add up to 90… not sure.
What you want to do is File-Export-Quicktime Movie — current settings self contained or not… doesn’t matter.
Drag THAT file into iDVD and let it compress it for you. It might work, it might not.
Good luck,
CaptM