The current Semantic Web ontology language has been designed to be both expressive for specifying complex concepts and decidable for automated reasoning. In recent years, the Semantic Web Rules Language has been proposed to add more expressiveness to the family of ontology languages. However the inclusion of rules has created new challenges of not only verifying the consistency of an ontology, but also checking for anomalies of a set of rules by itself. Currently automated tool support for reasoning about ontologies with rules is relatively limited compared to those for standard ontology reasoning. This paper addresses these challenges by defining notions of rule anomalies and proposing a method of discovering such anomalies by using the constraint logic programming technique and the state-of-the-art Semantic Web reasoners