Problem Monitoring Tomcat 6

Hi everybody!!

I'm trying to configure a Tomcat Server monitor in AppManager 9. I set all fields:
Host Name, Port, Tomcat Version, User Name, Password, everything is "OK", when I click "Add Monitor(s)", the Status return "Failed".

I click in "Diagnose the Problem?", but the diagnostic page shows:

Ping Test -> OK
Host Detail -> OK
Service Status -> Return a Tomcat's Welcome Page in HTML code (I don't know why, this is my problem.)
Authentication Details -> OK.

The monitor server and the tomcat server are under Linux Red Hat 5 and the same network. If I use lynx program to connect to the tomcat port I don't have problem and even I can access to manager context with a login

If someone had that problem and could fix it, I will be grateful, is very important to me set this monitor.

Thanks a lot.