>> Your provided script works for me with Firebird 2.1.2 CS. MY_USER is
>> able to query both views.
>>

It doesn't work with Firebird 1.5 :-(((

>> * Did you commit your GRANT statements?
>>

Yes.

>> * If you did a commit, then does it help to start a new transaction in
>> the session where you are running the SELECT * FROM statement?
>>

That is automatic for me - I am using a different tool for DML and a
different tool for DDL, so I always have a different connection and a
different transaction.

>
> And third, in CS you might need to re-connect, otherwise the already
> established connection probably won't see this metadata change.
>

That is also automatic.

Pepa Kokes