Tascam cdrw5000 finalizing problems

I own a tascam cdrw5000 and it worked fine, put of the blue it.stopped finalizing the disc. I press finalize and the countdown would begin, then right as its about to finish the time jumps back up and it continues to do this over and over. Now when I press finalize it flashes finalize a few times on the screen and then just stops, doesn't even attempt to finalize, any idea why it is doing this? Thanks!