Description:
------------
Exception thrown when issuing SELECT query using PDO driver 
for Firebird/Interbase. Database Server runs Interbase 7.5.x 
(Linux).

Problem occurs with PHP 5.1.2 running in both Linux/Apache 2 
and Windows 2000/IIS environments.

Tried running PHP alternately with Interbase 6 and 7.5 Run-
time Client Libraries on each platform; same problem.

Native PHP Firebird/Interbase functions (e.g., ibase_connect
(), etc.) functions work fine in same environments used to 
test PDO functions.

Confirmed DSN string used in my PDO connection function is 
correct by testing PDO::ATTR_CONNECTION_STATUS attribute; 
value returned is 1.

Reproduce code:
---------------
try {
  $dbh = new PDO($dsn, $user, $password, array(
    PDO::ATTR_PERSISTENT => true
  ));

  $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

  $stmt = $dbh->prepare("SELECT Count(*) FROM MY_TABLE");
  $stmt->execute();

  $row = $stmt->fetch(PDO::FETCH_NUM);

  $stmt = null;

  echo $row[0];
}
catch (PDOException $e) {
  die $e->getMessage();
}

Expected result:
----------------
Should output integer value result from SELECT query to screen

Actual result:
--------------
Outputs the following error:

SQLSTATE[HY000]: General error: -804 Dynamic SQL Error SQL 
error code = -804 Incorrect values within SQLDA structure