What versions are you using ? I assume you're using a JBoss 2.x- Tomcat 3.x bundle. Maybe you should switch to Tomcat 4.x, because the file-names of the generated servlets are actually much shorter than they were under Tomcat 3.x.
Hope it helps,
I switched to the bundle using tomcat4.0 and that fixed my problem. Why is the JBoss2.4.3_tomcat4.0 bundle not linked to on the jboss.org/downloads page? It is only on the sourceforge site, so I didn't see it at first.