change your DefaultDS.
I have in. i can use my own datasource, in \jboss-4.0.4.CR2\server\default\deploy\postgres-ds.xml i am using my own name, but its still picking up die default also
To disable Hypersonic, remove the hsqldb-ds.xml file from the deploy directory.
Of course, you will then also have to disable or change any services that depent on DefaultDS, such as the EJB timer service and JMS.