Some things like this happened when I played FF8 on my friend's dusy ol piece o' crap playstation. The PS would only read the disc when it wanted to, or when I smacked the side of it with my hand.

Im serious, when the game starts to freeze, or looks like it isnt loaded all the way, lightly tap the side of your PS with you hand. It should get the CD to skip and load the scene ( or whatever your doin ).

Best of Luck!