that number is almost exactly (off by only a few) from the size of 2 32-bit integer values, maybe that's a long float? i am not sure of the sizes of the variables, but yeah, that's an underflow error it looks like. basically when a number exceeds (or goes below) the range a variable can hold, it will start over at the min (or max, in this case) value it can hold. 2 to the 33rd power, or 2 32-bit registers, would give that number. try creating the project from scratch, and if it still does it, submit the problem to apple.