Blank Pages Using Purchase Orders V3.12

i am using 1.3.9f version.
Added purchase orders c3.12 with ty tracker and the two purchase order pages show up blank. The first one is send_pos.php.
I get the follwing error in the cache folder and need to know how to resolve it. [19-Sep-2010 14:37:35] PHP Fatal error: Cannot redeclare zen_get_products_manufacturers_name() (previously declared in /homepages/0/d176020969/htdocs/EZINKS/admin/send_pos_nc.php:16) in /homepages/0/d176020969/htdocs/EZINKS/admin/includes/functions/general.php on line 3437

Where do i need to rename zen_get_products_manufacturers_name() only in the send_pos.php file or in other places too?
thanks

I had the same problem. This is how I fixed it:

admin/send_pos_nc.php

line 16

Before:
function zen_get_products_manufacturers_name($product_id) {

After:

function manufacturers_name($product_id) {

I hope that helps.