If it's new, return it. If not, invest in a better quality dvd player.

I would suggest unplugging and re-plugging the player. I know that sounds dumb but I've had odd problems that seemed terminal go away just from unplugging and re-plugging things. The tracking circuit may have just gone out to lunch on it's own, or there may have been a minor power surge that sent it into a "flutter". These things happen. Unlike cleaning tapes for VHS tape recorders, those cleaning disks for CD/DVD players ONLY clean the actual laser head-if there's any grime in the mechanical grime on the laser head tracks that the head slides on, or on any of the gears or belts that move the laser or turn the disk, a cleaning disk won't fix that. Try one of those compressed air cans, and spray it into the door while it's open. Some drawer loading DVD players have a U-shaped cutout in the drawer that faces the player. This will make the task easier. You should NOT hold the can upside down because otherwise some of those air cans will spray the propellant liquid out of the tube, which can ruin the player. Ditto if the can is shaken before using. Some non-recording DVD players may have trouble playing home-recorded disks. Try a pre-recorded disk instead. Another possibilty is that a gear or belt is worn out inside. This will mean you'll eventually have to replace the offending part. If you can find the right one and you know how to replace it, the part itself probably won't cost that much. If you open the player, you should clean everything mechanical with a Q-tip and rubbing alcohol. However, don't try to "shotgun" the problem by oiling/greasing everything in sight! If you add any, you should only add a small amount. If the player has very high milage, the laser head itself may be reaching the end of the road. they usually slowly deteriorate-so it's probably not going to die tomorrow, unless the dropouts are severe. If the laser head is in fact bad, it's time for a new DVD player. Getting that done professionally will almost certainly cost as much as a new DVD player, and even doing it yourself may not be justified due to the cost of the pickup itself.