Hey, my friend has a Sony dru-700a DVD burner and he has burned well over 200 disks with it so far. Lately he's been getting a higher percentage of randomly unplayable coasters or movies that skip heavily part-way through. We have chalked this up to a dirty DVD burning lens because he consistantly uses TY disks, which are said to be one of the best. He switches between +R and -R burning now and then because when he burns movies for me, I give him my +R's, but for himself he uses -R's. The random unplayability and/or skipping seems to occur evenly as often using either media. So my question is, what is the best way to go about cleaning the burner's lens? We can't seem to find any of those CD/DVD Player Cleaning kits that say they can be used on DVD burners, but are they ok to use anyway? Which brand of cleaning kit is supposed to be any good? Or is there some make-shift way to do it, that is a little gentler?