What version of JBoss, Tomcat and Struts are you using?
Jboss 3.2.3 , tomcat 5.0 And Struts 1.1
The problem i have with the memory leak is solved. I downloaded struts.jar v1.1 from apache and for some reason the struts.jar file i downloaded has different size than what i had (v1.1).
Anyway the struts.jar file out there on Apache website fixed the memory leak problem using logic:iterate tag.