There are a number of places in the UserTransaction initialisation and TxPropogationContextUtil
that are doing jndi lookups() without closing the initial context.

Typically

new InitialContext().lookup(...);

This is inefficient since on the client side this will mean an rmi connection is open
until it gets garbage collected.

This has already been fixed in JBoss5 for the TxPropogationContextUtil (correct code should look like this)

try
{
InitialContext ctx = new InitialContext();
try

{ tpcFactory = (TransactionPropagationContextFactory) ctx.lookup(EXPORTER_JNDI_NAME); }

finally

{ ctx.close(); }

}
catch (NamingException e)

{ throw new RuntimeException("Unable to lookup " + EXPORTER_JNDI_NAME, e); }