Description:
------------
PDO::fetch() only returns date fields on the first call. 
subsequent calls return empty strings instead of dates. 

Configure Command =>  './configure'  '--
prefix=/usr/local/php' '--with-apxs2' '--without-pdo-sqlite' 
'--without-mysql'

php.ini-settings don't seem to matter, I only have these:
date.timezone = "Europe/Berlin"
include_path = "/Library/WebServer/php-includes/"
allow_call_time_pass_reference = Off
expose_php = Off
magic_quotes_gpc = Off
register_argc_argv = Off
output_buffering = On
plus settings for xdebug, apc and memcache, I already tried 
disabling them, no difference.

PDO_FIREBIRD is loaded as an 
extension:extension=pdo_firebird.so

Reproduce code:
---------------
isql:
SQL> create database 'test.fdb';
SQL> CREATE TABLE FOO (ID INTEGER, BAR DATE);
SQL> INSERT INTO FOO (ID, BAR) VALUES ('1', '11.04.2009');
SQL> INSERT INTO FOO (ID, BAR) VALUES ('2', '12.04.2009');
SQL> INSERT INTO FOO (ID, BAR) VALUES ('3', '13.04.2009');

php:
<?php
$oPDO = new PDO(      'firebird:dbname=localhost:test.fdb;charset=ISO8859_1',
        'sysdba',
        'masterkey',
        array(
                PDO::ATTR_PERSISTENT => true,
                PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_OBJ
        )
);


$oStmt = $oPDO->query('select id, bar from foo');


foreach($oStmt as $oRow)
{
        var_dump($oRow);
}
?>


Expected result:
----------------
object(stdClass)#3 (2) {
  ["ID"]=>
  string(1) "1"
  ["BAR"]=>
  string(10) "2009-04-11"
}
object(stdClass)#4 (2) {
  ["ID"]=>
  string(1) "2"
  ["BAR"]=>
  string(10) "2009-04-12"
}
object(stdClass)#3 (2) {
  ["ID"]=>
  string(1) "3"
  ["BAR"]=>
  string(10) "2009-04-13"
}

Actual result:
--------------
object(stdClass)#3 (2) {
  ["ID"]=>
  string(1) "1"
  ["BAR"]=>
  string(10) "2009-04-11"
}
object(stdClass)#4 (2) {
  ["ID"]=>
  string(1) "2"
  ["BAR"]=>
  string(0) ""
}
object(stdClass)#3 (2) {
  ["ID"]=>
  string(1) "3"
  ["BAR"]=>
  string(0) ""
}