PGConnectionPoolDataSource is not a DataSource?

I'm trying to use the PostgreSQL JDBC driver in an Orion AS environment with JTA and a JNDI bound PGConnectionPoolDataSource. I'm getting a ClassCastException, because Orion apparently tries to cast my PGConnectionPoolDataSource to a DataSource. The Oracle JDBC driver works, since the OracleConnectionPoolDatasource extends the OracleDataSource, which itself implements DataSource. javax.sql.PooledDataSource itself does not extend DataSource, and maybe there is a very good reason for this. But PGConnectionPoolDataSource extends BaseDataSource, which does not implement DataSource. I'm wondering why, because all its methods seem to be there. If anyone has a setup op Orion combined with PostgreSQL and JTA/JNDI, I'll be interested to hear.

---------------------------------
Yahoo! Autos. Looking for a sweet ride? Get pricing, reviews, & more on new and used cars.