By default, ColdFusion MX will try to answer any URL request for /servlet/*, which may cause an error or unexpected result. The workaround is to disable the ServletInvoker mapping in default-web.xml.
The ColdFusion Server configuration and J2EE configuration on JRun are configured to answer all requests for /servlet/*. This becomes problematic when installing and configuring ColdFusion with a web server with the same servlet mapping. The ColdFusion/JRun web server connector will intercept the request, even though ColdFusion is not specifically configured for the servlet.