[rules-users] 3.1-M1: java.lang.VerifyError: Shadow Fact problem?

Hi, It never rains it pours! Given a very simple rule:- package drools.debug rule "Test1" when $m : Machine ( ) then System.out.println("--> DEBUG!"); end Throws a very unfriendly error:- Exception in thread "main" java.lang.VerifyError: (class: drools/debug/MachineShadowProxy, method: setProperty signature: (Ljava/lang/String;JLjava/lang/String;)V) Register 3 contains wrong type at java.lang.Class.getDeclaredConstructors0(Native Method) at java.lang.Class.privateGetDeclaredConstructors(Unknown Source) at java.lang.Class.getConstructor0(Unknown Source) at java.lang.Class.getConstructor(Unknown Source) at org.drools.base.ClassObjectType.getShadow(ClassObjectType.java:123) at org.drools.reteoo.ObjectTypeNode.assertObject(ObjectTypeNode.java:148) at org.drools.reteoo.Rete.assertObject(Rete.java:121) at org.drools.reteoo.ReteooRuleBase.assertObject(ReteooRuleBase.java:196) at org.drools.reteoo.ReteooWorkingMemory.doAssertObject(ReteooWorkingMemory .java:68) at org.drools.common.AbstractWorkingMemory.assertObject(AbstractWorkingMemo ry.java:724) at org.drools.common.AbstractWorkingMemory.assertObject(AbstractWorkingMemo ry.java:543) at drools.debug.Setup.main(Setup.java:42) The Machine Class does extend another that has assessors for a Class that has lots and lots of constructors... Complete, self contained JAR, file available on request (a new JIRA?) Thanks, Mike