[rules-users] Weird drools exception happens from times to times

Hi guys, This exception is bothering me. I have a server running drools in after few days, drools starts throwing it and I have to recompile all the knowledge packages to make it work again. Does anyone knows what is triggering it? Thanks in advance. SEVERE|glassfish3.1.2|javax.enterprise.system.std.com.sun.enterprise.server.logging|_ThreadID=25;_ThreadName=Thread-2;|java.lang.ClassCastException: org.drools.reteoo.FromNode cannot be cast to org.drools.reteoo.BetaNode at org.drools.reteoo.ReteooBuilder.resetMasks(ReteooBuilder.java:303) at org.drools.reteoo.ReteooBuilder.removeRule(ReteooBuilder.java:267) at org.drools.reteoo.ReteooRuleBase.removeRule(ReteooRuleBase.java:459) at org.drools.common.AbstractRuleBase.removeRule(AbstractRuleBase.java:1107) at org.drools.common.AbstractRuleBase.mergePackage(AbstractRuleBase.java:851) at org.drools.common.AbstractRuleBase.addPackages(AbstractRuleBase.java:610) at org.drools.reteoo.ReteooRuleBase.addPackages(ReteooRuleBase.java:472) at org.drools.impl.KnowledgeBaseImpl.addKnowledgePackages(KnowledgeBaseImpl.java:150) Paulo Reis casmeiron(a)gmail.com