I have had the same problem since early last year, but I have never seen a response on how to get the bug fix or any suitable work-arounds.
The only thing that I have been able to do so far is to increase the <max-bean-age> from 600 to 1800, which has prevented most (but not all) users from experiencing the problem.
Can I use another cache policy, get a bug fix or use another work-around?
I recently tried upgrading from JBoss 3.2.0 to 3.2.3, but some things stopped working in our JSPs because of the switch from Jetty to Tomcat.
Open source is great, but sometimes it is defintiely more challenging too!