Swap discs and I believe many cheat discs are infact unlicensed products. The discs need to be pressed, it isn\'t a matter of dyes and such, there\'s information pressed (code and errors) that cd burners can\'t write. There\'s, in the case of some DVD players, ways that the laser intensity is adjusted and/or firmware coded that makes physically reading +/-R media impossible. But that\'s not really relevant to PS2.