The <param> tag does not appear to properly validate nested parameters. If I have the following definition:
<action name="manage" class="MyAction" method="myMethod">
<result name="success">/success.jsp</result>
<param name="param.nestedParam">foobar</param>
</action>
.. the plugin does not find the nested parameter (in this case, param.nestedParam). If I remove the nested parameter, the plugin does correctly find the containing parameter (in this case, param). Nested parameters are supported in Struts 2.0.