Originally posted by Winter
It would push the ps3 memory past the recommended limit for dev's, But thanks for this information :p
The memory locations in game space are all virtual. There is only about 192 megs of ram available, if the locations were real you would have problems long before 0x80000000 as that represents 2 Gbs of ram. Many games place their stack space in the 0xD0000000 range. The latest PS3 compilers are using 32 bit addressing since the 64 bit addressing was just wasteful.(that is why there is an option to turn 64 bit addressing back on in the ProDG debugger for older code).
A much more likely reason is 0x7fffffff is the highest positive number a int32 can hold and 0x80000000 is negative. This is probably causing an error somewhere in the version of NetCheat he is using. But I am only speculating of course, but it is the first thing I would look for considering there is code that is 64 bit addressed and any cast would extend the sign if he wasn't using unsigned ints.