I'm using the DVD burner that came with my Gateway 420. Whenever I put in a dvd or cd to copy, if I put in a new disc to copy it thinks it's the same disc. This doesn't usually matter with DVDs because I can select the folders to put the files in, but when I backup my cds with WMP, it erases all the songs of the original cd and replaces them with the songs from the cd I've just put in. How can I fix this?