The sized-integer types (I8, I16, I32, etc.) have a limited set of
functionality in LabVIEW 8 MathScript and we are considering improvements
for a future release. For now, you can change the data type of your
input to double (DBL) as you did in your example, or drop a conversion bullet
to a double value before wiring to the MathScript node.
--Sam
Sam Shearman