Env: Spring 2.5.x, JDK1.6

Am running into a number of problems pertaining to RMI registry
when remoting my MBean server using RMI. In particular, if I have two
MBean servers in the same servlet container (say, one in each
webapp context), I need two different RMI ports and hence two
different RMI connection factory beans (please correct me if
this is wrong).

This often leads to "InstanceAlreadyExists" exception.

If my apps run over JRE1.6, can I use JMXMP (JSR-160) for
remoting? I understand that commonly used JMX clients
(JConsole, MC4J) may not be able to connect to my servers.
The client I will use would be a Java client based on J2SE6.

Regards, /Uma