When reloading rules in a KnowledgeAgent declared facts will cause ClassCastExceptions when new-instance is set to false. When new-instance is set to true, the KnowledgeBase is rebuilt, however declared facts are not recognized and associated rules will not fire. Rules not using declared facts will fire normally. Using POJOs works fine.
In both cases the KnowledgeAgent will build the rule base the first time, the issue only seems to occur when the changeset resources are modified and are detected by the resource notifier and scanner.