SCPH-30003R series messiah chip probelms

[hydralore]

ok my ps2 is a SCPH-30003R and it has a messiah chip

iv bought gran turismo 4 and iv been told that i have to dissable the chip by holding in the reset button for 7secs to get the game to work (this is by dissabling the chip) . but it wont work i just get the no cd menu and when i click browser all it says is READING DISK....thats wether or not i try to turn of the chip....i also tried it with a copy game to make it not work but yet again it didnt work, so i was wondering if anyone knew why this is happening ?

cheers, hydra