I have an early edition iMac 20" (CD2)... Everytime that I try to burn a DVD+R DL disc, I get errors... Burning CDs or regular DVDs isn't a problem... This problem started recently.. I was able to burn them before... Is my drive gone bad and time to be replaced? This happens when I try both Disk Utility and Toast... The drive is a MATSHITA DVD-R UJ-846.... If it needed to get replaced, what's recommended?