SOLVED: The server didn't send back a proper XML response (2

I had this error but with the 200 response code and i found this solution that might help others. I found this answer here so i post as it is cause it was the exact case for me as well. i found the answer http://drupal.org/node/245231#comment-984249

Use the default version of conector.php and change the SetXmlHeaders() function in basexml.php.
Add the following:

  if (!function_exists('ob_list_handlers')) {
    @ob_end_clean();
    header("Content-Encoding: none");
  }
  else if ($handlers = sizeof(ob_list_handlers())) {
    while ($handlers--) {
      @ob_end_clean();
    }
    header("Content-Encoding: none");
  }