I have Sonic MyDVD - Serif version. The FAQ's do lead to the Roxio site.
I had a similar problem with a movie edit program (trying to remember whether it was MyDVD) and also found that I was in a loop. In my case a simple reboot wasn't the answer and actually had to turn the power off after which the problem vanished.
Not a direct answer to your problem I'm afraid but I've moved it up.