Hi Claudio,
Of course, you can debug the process, checking what is missing in your configuration (though, as I said, at the first glance everything is in order). You can set a trace (via ST05), introduce your contract and then analyse the trace in ST05, checking where the system is verifying the configuration for EMF integration and setting breakpoint there. Then, you can repeat the registry of the contract and, hence, discover what is wrong. This requires a bit of debugging skills in ABAP, though.
Regards,
Eli