> If you are interested I can send you the jar file of the ejb
> application, or you can take it from the jboss tutorial. You have to
> tune hibernate.properties file for use the Firebird connection.

Sorry, I do not have time to check this, but it would be great if you could
discover why JBoss/Hibernate accesses that table from multiple connections
when changing metadata.

This error message means that one connection tries to change the metadata
for the table while another connection has an open statement referencing
that table. Usually metadata changes require exclusive database access.

Roman