No, nothing wrong. According to Antoine, one of Carrara's creators, boolean's are notoriously problematic, even in other modelers. His suggestions include: increasing the poly count of the objects and then decimating after the operation; Increasing the Fidelity settings for the operation; trying to use the spline modeler if appropriate, and finally, avoiding booleans if possible. Most of the funky artifact issues are a symptom of too low a poly count on the faces being changed by the boolean, however. Mark