Did you notice that the number 4294967295 is equal to
2**32-1?  I suspect that some sloppy programmer
declared a 32-bit unsigned integer when s/he should
have declared a 32/16/whatever byte signed integer.
I'd almost bet the return code you're looking at is
really supposed to be -1 (negative unity).  Maybe that
will give you a place to start looking.

Good luck.