Supposedly lines 744-748 would be replaced.

The original content though was:
Code:
      if (trim($this->transaction_id) != '') {
        $sql = $db->bindVars($sql, ':transID', substr($this->transaction_id, 0, strpos($this->transaction_id, ' ')), 'string');
      } else {
        $sql = $db->bindVars($sql, ':transID', 'NULL', 'passthru');
      }
There may still be other things to be updated if you look at the upgrade path or file for ZC 1.5.5f. For some reason I thought there was still something modified in that file to further support the range of environment expected for the 1.5.5 series.

But, I'm drawing a blank at the moment, sorry.