I know nothing of Fedora, but those guy's will get to this message in a few, and they'll give their thoughts as well. Right now, the only thing I can tell you is to check to make sure the .iso image you burned to a disc is 100% okay. You do this with it's md5sum or CRC depending on which they have for it. This makes sure the .iso is in perfect condiditon, and not faulty. You should also do a file verification after you burn a disc. Can't excatly do that now, but you can at least check to make sure the .iso on your HDD is correct.