Script Assertion adding two decimal values suddenly is failing

So this worked last week (no changes other than the WSDL did change)...

CODE (abbreviated)

I have 3 defined (context.expand) values that are all decimal 

def a = context.expand(<path>) as int // = 43680.59

def b = context.expand(<path>) as int // = 3000

response = context.expand(<path>) as int // = 46680.59

def total = a + b

assert total == response

Run Error = "For input string: "43680.59"

Why is this suddently not working?

IF I remove the "as int" - it runs but it's "combining"/"concatinating" a & b together as strings

Thanks for your hlep in advance