title: Weird error when executing MSSQL prepared query
body: <p>I've got an issue with odbc_* functions. This is the first query I've had the issues with. 
  I have the following code:</p>
  
  <pre><code>$conn = odbc_connect('DSN', 'USERNAME', 'PASSWORD');
  $stmt = odbc_prepare($conn, "
      SELECT *
  FROM Table1 AS a 
      INNER JOIN Table2 AS c 
          ON c.StudentId = a.StudentId 
              AND c.ContactId = ? 
              AND c.SetId = a.SetId 
      WHERE a.SetId = ? 
  ");
  
  $result = odbc_execute($stmt, array('14153', '2013/2014'));
  </code></pre>
  
  <p>This however, produces the error:</p>
  
  <pre><code>Warning: odbc_execute(): SQL error: [Microsoft][ODBC SQL Server Driver]Invalid parameter number, SQL state S1093 in SQLDescribeParameter
  </code></pre>
  
  <p>If I remve the <code>c.ContactId = ?</code> and dont bind the value <code>14153</code>, then the query works fine.</p>
  
  <p>However I bind the same value on another query and it works fine! </p>
  
  <p>Does anyone know what this error indicates? 
  Many thanks</p>