Just picked up a retail copy of gt4, and suprise suprise, it doesnt work. I have tried it on 2 other ps2s and it works fine. I have a messiah mod chip in my ps2 could this be an issue>? Or could i get it to work perhaps by somehow getting it down to the single layer dvd size. My ps2 a few years old and im thinking this may have have something to do with its ability to run dual layer discs.