You might try this discussion forum
http://discussions.apple.com/categor...categoryID=128

That's the first place I go.

Did you check the permissions? Highlight the iDVD in the applications folder and either click on the i in the toolbar or click command i. That will bring up a long box. At the bottom there is a box that says ownership and permissions. Try unlocking the owner file. (You should be logged in as administrator to do this.)

Is there a reason you have set up three users? I find this annoying. (Of course, I find a lot since OS 6 annoying. Oh well. I liked extensions.) And, on the other hand, I remember writing FORTRAN programs for an IBM 360 that had 512K of memory and took up an entire huge room with tape drives. Yes, I am old, old, old.