ITUNES WON'T LET ME BURN A CD! HELP..

I've burned CD's before, many of times, & it's worked.. but for some reason now, when I go to burn a CD, it doesn't work! The discs are blank, & it'll burn the first song of my playlist, but after that, it stops & sits there doing nothing for about 5 or 10 minutes & then it'll say "canceling disc burn this make take a few seconds." It's doing that EVERY time now! Someone please help me!