If that method doesn't work, try raising the voltage for the laser of the offending type of disc (DVD or CD). You can find a guide for it here (either of the disc read error FAQs). My PS2 (SCPH-30001) was having a very hard time reading GTA: SA after I played GT4 on it for a month or so. After I cranked up the DVD laser voltage a wee bit (90 degree turn or so :heh: ), the game was almost back to normal (still has some minor loading problems when traveling at very high speeds).