Recent Sources is Disabled

Hi,

I am building a model based on our Microsoft Dynamics CRM Online data. I have two tables in my model already and would like to add some more from the same source but the Recent Sources button is disabled. The existing source is based on an oData connection. This works and I can refresh the model. When I click Get Data I am not offered the option of using my existing source. I suppose I could add another, identical, oData source but this seems inefficient and I wonder if it will cause problems later. I don't know for sure at this point all the tables that I will need in the model so I will probably have to go through this exercise again soon.

Is this the way it us supposed to work or is my model corrupt?

Thanks

Ian