For starters, posting the same question in multiple forums is not recommended for it can cause some confusion.
Second, panicing is not going to solve any problem, in fact it can make things worse. And since this is your first DVDSP project, how much of the manuals have you read? What version of DVDSP are you using?
You were able to complete a project in DVDSP, and were able to build, which tells me that the software seems to be functioning properly to this point. How big is your project?
When you insert your blank DVD, what do you tell finder to do? Do you have the disc mount? Do you tell finder to ignore the disc? (I tell finder to ignore)
In DVDSP, are the build logs reporting any errors?