very interesting discussion of tomcat classloader leak that leads to running out of PermGen

Must read deeply and test (-client seems an easy test)

Update -
Ok, -client doesn't work for me. OTOH, this is an old article (2005). No doubt a lot has changed with Java garbage collectors (and maybe less, but still some changes in Sun java API/JVM implementations). -client is actually significantly bad, compared to -server.

Time to look at org.springframework.web.util.IntrospectorCleanupListener