Did you try the usual cleaning with canned air then the usual CD/DVD lens cleaner?
I find that many never do this since it's slightly advanced (might require a philips screwdriver) or they never heard about it.
There's also that issue of fingerprints and scratches on media but that's well discussed.
Our Toshiba DVD player has recently started shutting down when you try to play certain movies. Some movies it plays just fine,but every so often you'll have a movie you try to play, and it will start like it is going to work, but then it will pick a particular spot and the whole machine shuts off. If you keep trying that same movie, it shuts off in the same spot every time. Toshiba won't talk to me about it because it's out of warranty. The stupid thing is not that old, so I'd rather not get rid of it. Any thoughts?