Hi, Roman!
I'm experimenting with the JBoss EJB3 preview 5. The application is
from the JBoss ejb3 tutorial, the one dealing with entity beans which
I have made it work with firebird.
The funny thing is that if the min-pool-size attribute in the
firebird-ds.xml file is set to 0 or 1, there is no problem with the
deployment. But when this number is 2 or more, or when there is
another active connection to firebird (apart of the jboss one) a
problem arises which says:

22:30:22,684 ERROR [SchemaExport] Unsuccessful: alter table LineItem
add constraint FK4AAEE947F4C206B8 foreign key (order_id) references
PURCHASE_ORDER
22:30:22,684 ERROR [SchemaExport] Resource Exception. unsuccessful
metadata update
object PURCHASE_ORDER is in use
Reason: unsuccessful metadata update
object PURCHASE_ORDER is in use

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.

Greetings
George