Web services not working after I enable App engine support in eclipse

I have a REST webservice which works fine handling a JSON string I send it and sending back a response ( I don't thing that it being a rest service is significant but I thought I should mention it )
I can run my app in hosted mode in Eclipse or as a standalone and both work fine. However, when I add Google App Engine support and rerun my web app, the JSON data being sent from the client is blank when I run entity.getText on the Restlet side. Nothing changed in code, just checked the GAE support properties box.
I'm guessing it's some JSON library I am using that does not work with GAE but I cannot tell for sure. Any one got any idea what else I could check for?

Thanks ..

Are you hitting the webservice from the client, or do you you client->server->webservice?

yes, I am hitting the restlet web service in both cases, with and without GAE support. With GAE support enabled the Representation entity is blank when I call getText on it in my Restlet POST method.
I have made sure I am using the GAE version of Restlet API