VQMod Install Error: Affiliate Class Not Found

When I modify the index.php file as stated in the directions, I get the following error:

Fatal error: Class 'Affiliate' not found in /hermes/bosweb26c/b2559/ipg.legendswebdesigncom/index.php on line 197

I have tried changing permissions to 755 and 777.

Here are lines 196 thru 202 in my index.php file
// Affiliate
$affiliate = new Affiliate($registry);
$registry->set('affiliate', $affiliate);

if (isset($request->get['tracking']) && !isset($request->cookie['tracking'])) {
setcookie('tracking', $request->get['tracking'], time() + 3600 * 24 * 1000, '/');
}

Here is my modification:
// vQmod
require_once('./vqmod/vqmod.php');
$vqmod = new VQMod();

// VQMODDED Startup
require_once($vqmod->modCheck(DIR_SYSTEM . 'startup.php'));

// Application Classes
require_once($vqmod->modCheck(DIR_SYSTEM . 'library/customer.php'));
require_once($vqmod->modCheck(DIR_SYSTEM . 'library/currency.php'));
require_once($vqmod->modCheck(DIR_SYSTEM . 'library/tax.php'));
require_once($vqmod->modCheck(DIR_SYSTEM . 'library/weight.php'));
require_once($vqmod->modCheck(DIR_SYSTEM . 'library/length.php'));
require_once($vqmod->modCheck(DIR_SYSTEM . 'library/cart.php'));


This is in my regular index.php, not the index.php admin file. As soon as I remove the modification, the store works fine, even with the modification in the admin index.php file. Anyone have any thoughts?? Thanks so much in advance!

Just a side thought, I am using the latest version of opencart, 1.5.1.3

after
require_once($vqmod->modCheck(DIR_SYSTEM . 'library/cart.php'));

add this

require_once($vqmod->modCheck(DIR_SYSTEM . 'library/affiliate.php'));