Problem with setting app pool

 I have created a package (zip file) which like to deploy to a web site (IIS 7). The package's parameters.xml file contains the following:

-<parameter name="AppPool" defaultValue="DefaultPool">

      <parameterEntry match="application/@applicationPool" scope="application" kind="DeploymentObjectAttribute"/>

</parameter> 

I use the following to deploy the package:

msdeploy -dest:iisApp='website/app' -source:package='base.zip' -verb:sync -enableLink:AppPoolExtension -setParam:'AppPool'='thePool'

I have other web.config parameters in parameters.xml and corresponding setParam in the command line. The app is created and all he web.config params are set correctly but the pool I specify is not set. It is always set to the same pool regardless of what I use in setParam. What I am doing wrong?

Thanks