Verisign Payflow module international filter problem (and solution!)

I installed the payflow pro module, and all of my orders were triggering the international filter in verisign, because the country was turning up as 'Unit'. This is because the Verisign country field is only four characters (confirmed by Verisign on the phone), and the payflow pro module was sending 'United States' as the country.

So I changed two lines in payflowpro.php, around lines 318 and 353 - the lines that set the billing and shipping country:

$tempcountry = zen_get_countries($order->billing['country']['id'],true);
$parmList .= "&COUNTRY=" .$tempcountry['countries_iso_code_3'];

and

$tempcountry = zen_get_countries($order->customer['country']['id'],true);
$parmList .= "&SHIPTOCOUNTRY=" .$tempcountry['countries_iso_code_3'];

it now seems to work fine. any better solution to this? i tried to access
$order->customer['country']['countries_iso_code_3']
directly, but that doesnt seem to be being filled, which is why i call zen_get_countries().