[rules-users] Newbie question / NoSuchMethodError error

Greetings, I'm new to Drools and I've written a decision table based rule using excel. The rule validates ok and I've deployed my package fine. I've written a piece of code to test my rules, I want to set the calculatedRate to 125 when I get selected field equal to "0 - 50" : ... StatelessSession statelessSession = rb.newStatelessSession(); Data data=new Data(); data.setSelected("0 - 50"); statelessSession.execute(data); // set private Integer field ... When I run the code I get a exeption : java.lang.NoSuchMethodError: java.lang.Integer.valueOf(I)Ljava/lang/Integer; I don't understand why Drools tries to convert to Integer something which is already Integer !!!! ----------- Here is the rules code. rule "setCalculateRate_11" salience 65525 when Data(selected == "0 - 50") then object.setCalculatedRate(125); end -------------- The CalculatedRate field is a java.lang.Integer object. Does anybody has an idea ?? Regards, Carl.