What is wrong with my DVD disc?

[Jonathan]

I have two DVD players at home and when I play this disc in one DVD player it says 'disc cannot be played on this player'. When I play it on the other player, it plays only for a while then it freezes and the player stops playing the disc. The disc is not region encoded so it should play on all DVD players. The disc is brand new with no visible scratches. The two DVD players I have are regular players, their not HD or anything like that.

[Matt]

its probably been scrached or is dirty first clean it if that doesnt work have it buffed or buy a buffer