Connecting to vCloud Director 5.1 with the REST api plugin

I'm unable to get this to work.

I'm following part of the instructions I found here: http://blogs.vmware.com/orchestrator/2011/07/vcloud-director-twitter-yahoo-and-foursquarecom-http-rest-plug-in-use-case-examples.html

So I install the plugin and run the workflow to add a host:

And set authentication for is with the "Set vCloud Authentication to a REST host" workflow:

And run the provided "Show a vCloud Director Organization" workflow:

And get the error: "No valid API version can be selected".

I also tried this with putting version 1.0 and 1.5 in the urls, but can't get it to work. What am I missing?

Thanks.