I'm seeing a similar behavior where existing SLSB instances were not re-used as expected. My application has a MDB that contains an injected SLSB for use during the onMessage() method. When onMessage() is called, it appears that a new SLSB instance is constructed. The MDB itself seems to be re-used correctly, and I'm not seeing this object leakage when I have a SLSB injected into another SLSB -- it only occurs within the MDB. This thread seems to indicate that this may be a bug with ThreadLocalPool: http://jira.jboss.org/jira/browse/EJBTHREE-1175?page=all Does using MaxStrictPool instead of ThreadLocalPool solve the problem? If so, can someone point me to some documentation about how to configure JBoss to use StrictMaxPool? What are the problems with using StrictMaxPool? Thanks, John View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4126785#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...