Under JBoss 4.0, deploying the bundled hsqldb-ds.xml automatically creates an MBean with the following ObjectName:
jboss.jdbc: service=metadata, datasource=DefaultDS
org.jboss.deployment.DeploymentException: Failed to obtain type-mapping metadata from the metadata library MBean: jboss.jdbc:service=metadata,datasource=BigDealDS is not registered.; - nested throwable: (javax.management.InstanceNotFoundException: jboss.jdbc:service=metadata,datasource=BigDealDS is not registered.)