This issue appears to be resolved. Ray figured out that it was caused by the use of a / in the name of the product. It seems that the / was somehow messing with PayPal's code or something.
On PP_PayAdv_PHP.php the variable for the name was like this
$vars[] = 'L_NAME' . ($item_count+1) . '=' . (substr(strip_tags($cart->DisplayInfo("Name")), 0, 36));
He added the urlencode to it
$vars[] = 'L_NAME' . ($item_count+1) . '=' . (substr(urlencode(strip_tags($cart->DisplayInfo("Name"))), 0, 36));
Things are working again.
Oh, and as for the failure page loading in the iframe. He added some javascript to the head that makes it break out of the iframe so it's loaded in it's own page.
if (window.location !== window.parent.location) {
window.parent.location = window.location;
}
Thanks for the help Ray!!!
TroyD