Fixed, thank you!
FYI, this is the code that is in the latest contribution and is what I used to add to the currencies.php file.
//Master Products
function display_price($products_price, $products_tax, $quantity = 1) {
if($products_price == '0') {
return '';
} else {
return $this->format(tep_add_tax($products_price, $products_tax) * $quantity);
}
//Master Products EOF
It's obviously different from the code you just gave me.