problemas freetds

["Sergio Villalba" <svillalba@cherrytel.com>]

hola lista,

tengo configurado un servidor apache 1.3 con el paquete freetds para
conectar base de datos sql server de windows.

El problema que tengo es que aparece este error a veces cuando conecto
con el usuario y contraseña a la aplicacion, este error sucede a veces y
no siempres:

Warning: 1 is not a Sybase link index in
/usr/local/apache/phplib/db_mssql.inc on line 82
Database error: Invalid SQL: update active_sessions set
val='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',
changed='20060124102051' where sid='4cb4a5a80f356d18d085c92fc9f3cb9d'
and name='Session' - Link-ID: 1 - Query-ID:
MSSQL Error: 1 (General Error (The MSSQL interface cannot return
detailed error messages).)
Session halted.

La variables del sybase las tengo así:
Sybase Support enabled
Allow Persistent Links No
Persistent Links 0/0
Total Links 0/unlimited
Application Name PHP 4.0
Client API Version $Id: dblib.c,v 1.160 2003/12/26 18:11:08 freddy77 Exp
$

En el fichero /usr/local/apache/phplib/db_mssql.inc tengo esto:

class DB_Sql {
  var $Host     = "";
  var $Database = "";
  var $User     = "";
  var $Password = "";

  var $Link_ID  = 0;
  var $Query_ID = 0;
  var $Record   = array();
  var $Row      = 0;

  var $Errno    = 0;
  var $Error    = "";

  var $Auto_Free = 0;     ## set this to 1 to automatically free results


  function connect() {
    if ( 0 == $this->Link_ID ) {
        //$cont = 0;
        //$max_conexiones = 50;
        //while ($cont < $max_conexiones) {
        //      $cont++;
              $this->Link_ID = mssql_connect($this->Host, $this->User,
$this->Password);
        //      if ($this->Link_ID) $cont = $max_conexiones;
        //}


      if (!$this->Link_ID)
        $this->halt("Link-ID == false, mssql_connect failed... ");
      else
        mssql_select_db($this->Database, $this->Link_ID);
    }
  }

  function free_result(){
          mssql_free_result($this->Query_ID);
        $this->Query_ID = 0;
  }

  function query($Query_String) {
    if (!$this->Link_ID)
        $this->connect();

   //printf("<br>Debug: query = %s<br>\n", $Query_String);

    $this->Query_ID = sybase_query($Query_String, $this->Link_ID);
$this->Row = 0;

    if (!$this->Query_ID) {
      $this->Errno = 1;
      $this->Error = "General Error (The MSSQL interface cannot return
detailed error messages).";
      $this->halt("Invalid SQL: ".$Query_String." - Link-ID:
$this->Link_ID - Query-ID: $this->Query_ID");
    }
....
....
etc

Alguna idea, ya no se que mirar o probar con pconnect.
Gracias por todo.
Un saludo.