Another issue while deleting a user with MDB2

There is another issue while trying to delete a user here is my error

ear Errors with the system
Info: MDB2 Error: error while including on demand module
[Error message: unable to find module: MDB2/Driver/datatype/mysql.php]

(/usr/local/lib/php/MDB2.php at line 875)
(/usr/local/lib/php/PEAR.php at line 540)
(/usr/local/lib/php/MDB2.php at line 1244)
(/usr/local/lib/php/MDB2.php at line 1558)
(/usr/local/lib/php/LiveUser/Admin/Storage/MDB2.php at line 177)
(/usr/local/lib/php/LiveUser/Admin/Storage/SQL.php at line 508)
(/usr/local/lib/php/LiveUser/Admin/Storage/SQL.php at line 448)
(/usr/local/lib/php/LiveUser/Admin/Storage/SQL.php at line 377)

On a closer look in Sql.php at this line in the createWhere method

     $where[] = $tmp_field.' IN ('.$this->implodeArray($value, 
$type).')';

implodeArray

  function implodeArray($array, $type)
     {
         $this->dbc->loadModule('datatype');
         return $this->dbc->datatype->implodeArray($array, $type);
     }

Its loading the datatype module, and looking for the file mysql.php 
however the file is there i have triple checked ??

this is strange because it all works fine on my system which is php 5.1 
and Mysql 5 but not on the production machine which is mysql 4.1 and 
php 4.4 any ideas ?