so ive been messing around with cIOSX rev20, and i am not sure as to what the base ios is, and which one i should be using. if anyone could explain, that would be great. also, i read on 2 guides to use IOS56 as a base, but when i do that, surprisingly, black ops loads forever, and the disk stops spinning. However, if i have ios57 as a base, then BO works fine. is the base ios a compatability thing?