Gavin, I am no longer sure if this is a seam problem after all, but a problem with drools. In rules 3.0.6 (the only source I could get my hands on), The Rule.isValid() has: if ( this.consequence == null || !isSemanticallyValid() ) { but nowhere in the code is the consequence set, so it is always null, and thus always invalid. The only time setConsequence is called is from PackageCompilationData from reload() and write(String, byte[]). These are only called by AbstractRuleBase.mergePackage(Package, Package) and PackageStore.write(String, byte[]) I am not familiar with drools, but does anyone have an idea, or is this indeed a bug in drools 3.0.6? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4057066#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...