Make the user db_reader and db_writer for the database

>Hi,
>
>I am having a problem using SQL Server authentication for my VFP application (note that the same app works fine with this type of authentication for other customers).
>Here is what I did:
>
>In the SQL Server Security created a User MyUserId. Set it for SQL Server Authentication.
>
>In the Database created User MyUserId and assinged it to the same Login, MyUserId. Set this user to role db_Owner and schema db_owner. But when I try to connect from my app using these credentials, the access is denied. I know I specified the server name and the database name correctly since if I change the connection string to use Windows Authentication, I have no problem connecting.
>
>What could be missing in this case?
>
>TIA