Thank you Norman.
I. Yes it didn't had a PK, but I tryed to add a record with "INSERT INTO..."
code, was not able to do it (while in the SQL Server Management Studio I
could do it with the code).
To make it through the code I use the procedure in the help under "Create an
update query (ADP)" in Access 2003. But when I go to the designer it gives me
the error I described originally. It doesn't allow me to drop tables, but
then I used the SQL code pane (didn't needed the graphical help this time),
once I wrote the code it didn't execute it (even though it parses it
correctly, with the "Verify SQL Syntax" buttom).
II. I also added a PK and tried both with the UI and the code.
Neither had worked so far.