Since it is free you should be able to find it through the net. Read up on it if you are unfamiliar. My bet is that the file wasn't downloaded incorrectly though, it's either the medium (The brand of DVD basically), or you are using a cruddy burning program like Easy CD/DVD Creator 7.
I had to try two different disks with Fedora and it did work, I am now running YDL 5 and that had no problems once I burned it to that type of disk. Try Using Alcohol 70% or 120% (or nero) even if you have to use the trial.