I keep getting CRC errors when reading DVDs. I can say retry and sometimes it will work. If not, I can pop the disk and reload it and it'll work again. Sometimes I may have to do this 3 or 4 times before it'll work again. Does this sound like a bad drive or a bad disk? It just started doing this a while ago. Someone mentioned that the drive might be out of alignment with the laser. Is this something that is fixable or should I just get another one?