Multiple Databases in a single model

We have a single model spread over multiple databases, mainly for physical reasons.

I've set the

          EnableManyDatabases

in the DBMS properties of the database.

The database name disappeared from the model properties as it said in the help.

     If your DBMS supports multiple databases in a single model (enabled by the EnableManyDatabases entry in the Database category of the DBMS),      this field is not present, and is replaced by a list of databases in the Model menu. A Database category is also displayed in the physical options of your      database objects.

and I have a list of databases from the Model menu.

However, I don't have a "Database category" displayed in the physical options of the database objects.

Can anyone tell me how to specify which objects is in which db ?

Thanks