Suddenly I cant burn CD's

After I succesfully have made several cd's from different playslists i get a error message "Reload a rewritable or bland Cd, Please replace the disc in the drive with a rewritable or blank CD."

During the last time it stopped halv way through the prosess, and I could hear the Cd still working, but i could'nt stop it ore eject the cd. So had to shut down the computer. Could this have something to do with it?
The thing is that i know for sure that the cd's i'm using is empty and have enough storage space for the files that i'm burning.

sorry, i'm such a nooob..

Can anyone help? :)