Debug error (create account) - cant find error

[PudzPud]

Nothing was changed on my site today but suddenly people cannot create a new account and instead get a blank page. Up until about an hour or two ago everything was fine with new accounts added no problem. I checked the ZC forums and as advised ran a debug which says:

[18-Nov-2011 16:50:35] PHP Fatal error: Call to a member function on a non-object in /home/otcafxm/public_html/includes/modules/beeunique/create_account.php on line 404


I have checked the php file and lines 403-405 say:
//look for an exact match on zone ISO code
$found_exact_iso_match_shipping = ($zone->RecordCount() == 1);
if ($zone_shipping->RecordCount() > 1) {

I cant see how this would cause the error the debug shows - is there a way I can locate it on the php page as reading through trying to find it is like reading another language. I don't usually do php side of things (my ex did before he was my ex) and although I can do basic things I am struggling with this and in the meantime nobody can create a new account on the site.

Any help appreciated

ADDED - this is not a new install and has been running for several years without this problem. it is also 1.3.9 if that helps any.