Preamble:
There is a similar but slightly different bug report 2976 that describes parameter passing problems as well.

Steps to observe behaviour:

1) In MS Access (preferably 97 or 2000) create a table named PEOPLE containing two fields
    username and password of any type.

2) Populate the table with a row of test data.

3) In MS Access create the following query name verifypassword:

         SELECT username
         FROM people
         WHERE username = InputUsername AND password = InputPass
         WITH OWNERACCESS OPTION;

        Since the DB is not going to be secured for any test cases, do NOT include the 
        WITH OWNERACCESS OPTION, as it is pointless and may not work.  When in a 
        secured database, this query will allow verification of a username and password 
        combination for a user that does not have access to the PEOPLE table without 
        giving direct access to the password field.  I provide this only for a description of
        necessity.

4) Make an ODBC DSN to the DB

5) In your PHP script connect to the DSN first, save connection to $conn.

6) In your PHP script, then add:

         $prep = odbc_prepare( $conn, "SELECT * FROM VERIFYPASSWORD" );
         $params = array( "test", "case" );
         ODBC_Execute( $prep, &$params );

7) You will get a "missing parameters" error.

Problem:
There is no appearant way to populate MS Access parameters from PHP.  
Since, in this case the query must be created under a user with priviledges to
a secured table, the query cannot be generated on the fly -- access will be denied.

Ideally, I should be able to populate my $params array as:
        $params = array( "InUsername" => "test", "InPassword" => "case" );

Synonymous behaviour in ASP:
In ASP the RECORDSET object supports named parameters.  
Obviously this functionality works in ASP.