Running tcpmon to debug Axis

I am attempting to run tcpmon to debug web-service traffic on my Tomcat (open 
source, not IBM-provided) server running Apache Axis on our iSeries.

1. Tomcat has successfully run on port 80 for a long time, utilizing Axis to 
provide web-services.
2. I can start tcpmon to listen on port XX (where XX is any uncommon port) and 
trace/forward traffic to Tomcat on port 80.
3. When I change Tomcat to listen on port XX (it successfully starts and 
responds), and try running tcpmon "in-between" (listening on port 80, 
forwarding to port XX), I always get "java.net.ConnectException: A remote host 
refused an attempted connect operation."

tcpmon appears to work on any non-common port, but fail when using well known, 
assigned ports (eg, 80, 443, 21, etc.)  No other iSeries process appears to be 
using the IP address (NETSTAT *CNN).  My web-service client *must* talk to port 
80, therefore I must have tcpmon listen on port 80 and forward to some other 
port.  I suspect my problem has something to do with service table entries.  
Can anyone help?

Thanks,
John