What do I do to fix this, iDVD isn't burning discs anymore?

I have burned quite a lot of discs using iDVD, and now it suddenly won't work. It started saying "Waiting for device to become ready" and it would say that for hours. I restarted iDVD and tried again and now it is saying "Your Macintosh does not have a supported SuperDrive" and says that I won't be able to burn a disc. This is really important, I have to burn this dvd! (it is video)