I have a Samsung Combo SM-304B CDROM/DVD Drive. It has worked fine for two years, but after a 3 month break i recently started using it again. The rest of my PC is fine, but the drive now no longer recognises CD/R or CD/RW media. DVD's perform fine and regular CD's are also okay (there is some skipping in tracks, which wasn't there before). Could anyone please advise on what the problem might be? Thanks.