Boolean Value Warnings in Java

 From the powerloom 4.0.0.beta command line in the module PL-USER I can:

(defconcept city)
(assert (city newyork))
(deffunction unhappy ((?c city)) :-> (?b BOOLEAN))
(assert (=(unhappy newyork)TRUE))
(ask(=(unhappy newyork)TRUE))

and get an answer of TRUE.

Attempting the same example above using the powerloom.jar that comes
with powerloom 4.0.0.beta gives me a warning.
If I ask "(=(unhappy newyork)TRUE)" with the method
PLI.sAsk in the module PL-USER I get the warning:

WARNING: Type check violation on argument `@TRUE' in proposition
    (= (UNHAPPY NEWYORK) TRUE).
    Argument must have type `BOOLEAN'.
    Warning occurred while parsing the proposition:
    (KAPPA () (UNHAPPY @NEWYORK @TRUE))

and an answer of TRUE.

Am I using the wrong values for booleans?
Is there any advice on how to get rid of these warnings?

Thanks for your help.
Lee Martie