Can some one tell me how to get this plugin working on zencart 1.5.1.

I am able to login to accounts of customers who have returned after they created their account. However, I can't seem to do the same for the ones who created their account but did not return at least once more.

I think it has to do with the issue from post #148 because I get this error: "Error: Sorry, there is no match for that email address and/or password" as well.

What should I exactly replace (php isn't my strongest point)?