Never experienced such a problem myself, but, yeah the thing needs some sort of lubrication. Problem is, I don't know what to suggest. I would be very reluctant to apply WD-40 or any petrolium-based product to a DVD player's sliding tray.
Anybody have any suggestions here? I certainly would be glad to hear them.
Meanwhile, Paul, I'm sure your player is otherwise okay. The squeeking noise doesn't portend anything bad, IMO.
a dvd player is just like any other cd players. you can just open up your player's cover, look for the sliding tray's railing and apply little oil. probably the friction is caused due to close contact with the railing the railing only comes in contact with the tray and not the lens. just make sure you dont apply too much oil (use a cotton bud) and dont touch the lens!!!