populateJMSXUserID=true and network of brokers

Hi,

I've the following:
- populateJMSXUserID=true in <broker />
- <transportConnector name="ssl"
uri="ssl://0.0.0.0:61616?needClientAuth=true"/>
- a network of brokers with four machines (full mesh)
- the clients and brokers authenticate themselves with certificates and
connect with SSL

If I connect with client A (producer) to broker A and client B
(consumer) to broker A (same broker), I get a JMSXUserID header with the
client's DN in the published messages.
If I connect with client A to broker A and client B to broker B
(different broker), I get a JMSXUserID header with broker A's DN in the
published messages.

How could be populateJMSXUserID turned off just for the inter-broker
connections? I've tried to specify a =false option to the URL without
success.
I would like brokers to leave this field intact on messages passing on
their links.

Thanks,