What did you use to clean your registry? What OS are you using, ie. 98, XP ect. ect. What program are you trying to burn with?
Sounds like you may have removed a/some registry threads that belong to your burning software. You may want to reinstall that software Or restore the threads you removed from your system registry Or if using XP, do a system restore.
I don't think you affected the drives firmware, but as a last try, reflash your drive again.