If the XML-RPC interface of QueueMetrics is not working, i.e you get no meaningfiul response, you have to look up the catalina.out file in order to detect possible problems.

Xerces not installed

With Java 1.5 and Tomcat 5.5, you may encounter the problem as an error string stating redstone.xmlrpc.XmlRpcException: Could not instantiate XMLReader parser. This means the Xerces parser cannot be found. If this happens, download Xerces from http://xerces.apache.org/xerces-j/ and put the file called xercesImpl.jar in your queuemetrics/WEB-INF/lib. This should solve your problems. (Thanks to Matt B. for input)