Just a varification
 

Holding down the power button for six seconds does indeed disable the apple chip. I did it today and it worked fine.

I also noticed before I did that I tried to play SWEP1 Dvd and it would not play. However once I disabled the apple chip the dvd played fine.

I don't know if SWEP1 is a dvd9 but it sure seems that way.

If thats the case then you need to disable apple to play dvd9 games.

Yeah you have to disable it for Xenosaga, which is a dvd9. Stick SWEP1 in your comp to see its TOC.