My DBI script wont UPDATE a Table!

[Mark Martin]

Hi,
I designed my application on a test database and it worked fine without commiting the 
database handle. But now when I've moved it to the production database my updates wont 
commit - even when I do issue a commit on the DBH?!?!

while(certain condition) {
                                    $sql = qq{UPDATE table SET field=value} ;
                                    $sth = $dbh->prepare($sql) ;
                                    $sth->execute;

                                    $dbh->commit();                                    
         
                                  }
$sth->finish;
$dbh->disconnect;

I've tried the commit outside the while statement with no luck. Any ideas?
Mark