http://www.gtplanet.net/forum/showthread.php?t=55927
A good number of people seem to be having issues with Gran Turismo 4. Some of these problems are most likely due to modchips not playing nice with dual layer disks, which are a rarity among PS2 titles. But a lot of folks can?t run the game, even on brand new systems. It just hangs. Other people are seeing horrendous skipping on the intro.
Sony seem to think there may be a bad batch of disks out there, but there are cases of people who have the game that works on one system, but not another.
I got the game, but I?ve not had a chance to test it yet. If you?ve bought it, have you had any problems? What model PS2?