Ok, here is my problem: I played this game 2 times without troubles. The third time i tried, it kept locking up. Now every time i try it just keeps on not loading!
Clean out your PS2. (Vacuum the dust/clean the lens.) I had to go to extreme measures just to play GT2 on PS2 once... I put beer in my PS2 then it worked like new. (Except it smelled like a Heineken. ) Then I had to clean it out again because it NEVER read any CD's I put into it. I threw alot of water into it and let it dry for 8 hours. Then it started to read a little bit and then completely stopped. I had to buy another one. Don't do what I do to fix my PS2's... trust me. (Except the Vacuuming/cleaning out the lenses.)
Maybe its just that your CD needs a good wiping or maybe it got scratched alot.