hmmm. I have no idea. I would say the safest thing would be to delete it all and start over. if you dont want to go to that level, then try deleting the tracker, re-download it and see if that makes a difference. Also try disconnecting and turning off your computer, let it sit off for a few minutes and then turn it back on, reconnect and see what your getting. <-just guesses.
The file is only 8.45 gig, so if your holding more than that there is a problem.