[rules-users] ClassCastException

Hi all, i've some problems with a ClassCastException when using the "or"-conditional element. I have different Java-Beans which all have some string-values. Now I want to create one rule which is able to handle every type of my classes because it would be a lot of work to create one rule for every class. Depending on the type of beans in the working memory the programm is crashing with an ClassCastException. Here is a snippet of my drl-file with the "crashing-rule": rule "BizLocation" when $epc : EPC() QuantityEventType(epcClass == $epc.value ,$bizLoc: bizLocation !=null ) or AggregationEventType(childEPCs.epc contains $epc, $bizLoc : bizLocation != null) or ObjectEventType(epcList.epc contains $epc, $bizLoc : bizLocation != null) then System.out.println("BizLocation: " +$bizLoc.getId()); end There are some EPC's in the working memory and some Events (which might be of type QuantityEventType, AggregationEventType or ObjectEventType). When there are only ObjectEventType in the working memory, everything works fine, but wenn there is an QuantityEventType this rule crashes with "org.fosstrak.epcis.model.QuantityEventType cannot be cast to org.fosstrak.epcis.model.ObjectEventType". I've lot of other, similar rules some of them crashing, others don't. Can anyone give me a hint where is the error? Thanks, Christoph PS: Sorry for the bad english :(