Most likely, the firmware on your DVD burner needs updating. You've probably aquired some 8x media and your burner only supports up to 4x burning, so the 8x media is confusing it. But, that's just a guess.
Go to the burner manfacturer web site and see if thier support section has some newer firmware that you can download and flash on your burner.
Strangely enough, the media I use have worked fine for the longest time. (Sony brand on a Sony burner)
The firmware on the Sony drive is the latest and I even tried to delete the drive and have the system find it after nect re-boot.
I'm thinking about simply getting a new burner. Any suggestions?