I get a fatal error

I get a fatal error when trying to access the Gift module in Order Total. I have the Gift Vouchers working. The only thing I can remember doing before the error was doing a test emailing from admin of a Gift Card to myself, purchasing a gift and changing file /includes/languages/english/gv-faq.php to include a link to the gv_send.php page. Oh and I deleted the Euro from currencies... other than that I don't believe I changed anything else

using zen v 1.3.0.2

Code:

Fatal error: Call to a member function on a non-object in /home/bishopba/public_html/cathis/includes/modules/order_total/ot_gv.php on line 29

my code around line 29:

Code:

if (!zen_not_null(ltrim($_SESSION['cot_gv'], ' 0')) || $_SESSION['cot_gv'] == '0') $_SESSION['cot_gv'] = '0.00'; $this->checkbox = $this->user_prompt . '<input type="textfield" size="6" onchange="submitFunction()" name="cot_gv" value="' . number_format($_SESSION['cot_gv'], 2) . '" onfocus="if (this.value == \'' . number_format($_SESSION['cot_gv'], 2) . '\') this.value = \'\';" />' . ($this->user_has_gv_account($_SESSION['customer_id']) > 0 ? '<br />' . MODULE_ORDER_TOTAL_GV_USER_BALANCE . $currencies->format($this->user_has_gv_account($_SESSION['customer_id'])) : ''); $this->output = array(); }

I tried re-uploading ot_gv.php and the gv_faq.php files but that didn't fix anything.

any ideas on how to fix?