Yesterday my MacBook started ejecting DVDs after I inserted them into the drive. They will go in, start spinning for 30 seconds or so then are ejected. However, the optical drive is playing CDs with no problem. I have tried several film region specific DVDs and an authentic Snow Leopard DVD with no joy. My DVD lens cleaner disc will successfully launch DVD player and I can then clean the lens but still it won't accept any other DVDs. One thing though, I left the MacBook off overnight and then tried a film DVD this morning and it did launch DVD player and started to play. When I ejected it and tried another one it reverted back to the original problem and I've had no success since. Any advice would be gratefully accepted.