VCO 5.5 REST and the Twitter API

Hey all,

I am attempting to call Twitter via VCO, following directions from http://www.vcoteam.info/articles/learn-vco/158-tutorial-create-your-own-twitter-application-with-a-vco-workflow-in-a-few-minutes.html. When I try and run any REST operation, I recieve error code 401. Any ideas for troubleshooting?

[2014-04-07 11:50:16.945] [I] Request: DynamicWrapper (Instance) : [RESTRequest]-[class com.vmware.o11n.plugin.rest.Request] -- VALUE : com.vmware.o11n.plugin.rest.Request@7c776831
[2014-04-07 11:50:16.945] [I] Request URL: https://api.twitter.com/1.1/statuses/update.json?status=Tweet
[2014-04-07 11:50:17.478] [I] Response: DynamicWrapper (Instance) : [RESTResponse]-[class com.vmware.o11n.plugin.rest.Response] -- VALUE : com.vmware.o11n.plugin.rest.Response@3264683e
[2014-04-07 11:50:17.478] [I] Status code: 401
[2014-04-07 11:50:17.479] [I] Content as string: {"errors":[{"message":"Could not authenticate you","code":32}]}
[2014-04-07 11:50:17.497] [I] HTTPError: status code: 401 (Workflow:Invoke a REST operation / Check status code (item3)#1)

VCO v.5.5.1

HTTP-Rest plugin v 1.0.3.337