I've recently have had problems with the slot loading DVD drives in my IMac Intel Duo & my wife's MacBook. They both were ejecting blank DVD's. I checked with Maxell tech support who purport to make an excellent DVD lens cleaner but they don't recommend using it in Apple slot loading DVD drives because it might dislodge or loosen the lens. I blew out my iMac drive with canned air & now it seems to work 90% of the time. Does anyone Know of a DVD lens cleaner that can be safely used in a MacBook? Apparently the MacBook is more critical than the iMac because it uses an ultra thin 9.5mm drive.