Nero 6 shows all my CD-R's as only being 7:07 minuters in length..?

Come guys, i need your help…!
I have just installed Nero6 and everytime i try to burn anything my Nero6 says my blank CD-R’S are only 7:07 minutes in length. They should be 80minutes. I have different brands, re-installing Nero6, no change. Is this a drive problem, nero6 problem or xp problem. I am out of idea;s what to try next.