Also, be sure to verify that the OData library is deployed on your server, I had to download it separately via Service Marketplace and deploy it to my NetWeaver instances. The SCA is named something like "SAP ODATA4J+CXF-REST LIB 7.31".
If you are on NW 7.30 it's named something like "SAP ODATA4J+CXF-REST LIB 7.30"
Sam