Might try using a little rubbing alcohol on a cotton Q-tip and VERY GENTLY clean the little "eye" (actually the lens). After you do this a couple of times, swab the "eye" a final time with a dry Q-tip and then blow a bit of canned air on it.
I'm a heavy smoker and am compelled to do this procedure about once every three months or so to remove the tar and "gunk" buildup that smoking causes.
If that does not work, try a music CD. If the only things that will be "played" OK are "stamped/pressed" CD's, this is an indication that the ODD has gone South on you and an RMA may be appropiate.