yeah my first copy did that. look at the disk in the light and you'll notice some discolor in it. you gotta look hard cuz its hard to see. but when you first got it i bet you had trouble gettin it out of the case huh?. you prolly bent it too much like mine did.
Either your game is defective or your lens is probably dirty and weak. You might have to clean it homie. Also it's recommended you stand your ps2 vertically since it gives your ps2 a longer life and also keeps it from getting the disc errors . Try using a dvd/cd lens cleaner. If that don't work follow this link to show you how to clean the lens manually.
u said it was re-released.....so outta curiosity....if i went to best buy tonight and bought GTA3, would it be censored, because i only heard of it cencored in australia, not in the states, but i could be wrong