Based on my experience with versions 3-4 the following all need either product activation and or registration. It can be totally transparent, or a pain in the ass as you have discovered. It depends on which method you use to "register" if the machine you are registering is online or not. If not, lots of luck, it can be a bitch to register.
Vegas itself needs to be "activated" and registered. The number that comes in the getting started booket or in the email if you got the downloaded version isn't the registration number, just a number that should lead to to another number that's part of the activaction. Having fun yet?
Plus the following may or may not demand they be registered seperately:
1. the MPEG encoder
2. the cookie cutter plug-in
3. the AC-3 encoder
4. the 5-1 surround plug-in
Call Customer Service. Everyone in the department goes to lunch and shuts down for a hour, they don't offer any "service" at night or on weekends.
But the encoder is in Vegas, not DVD? Both are registered. You can't move forward without doing that. I've tried every number I have. Shouldn't they have included a serial number in the package?
Install Vegas and DVDA, register both. At this point you will not be prompted for MPEG or AC-3 registration- you're all set and ready to encode to either.
I put DVD-A on one computer and Vegas on another. AC-3 is associated with DVD-A even though you can create it in Vegas. DVD-A must be on the same computer.