Need help with change address not functioning, losing customers!

[accension]

I'm working on a site for a client who is using Zencart, they had purchased a slighted outdated template which I think may be affecting the installation. Basically, in the website, nobody can seem to change their address. This is a huge problem and people are not fulfilling orders they intended to fulfill because of it.

http://www.whyrentbooks.com

Also, problem number two, when going from step 2 to step 3, the confirmation, it keeps kicking them back to step 2 with no error messages! What files do I need to restore from the clean 1.3.7 to make this work? Fyi, you can't currently test problem two on my site because I had to disable the credit cards.

[accension]

Update:

"You must select a country from the Countries pull down menu"

This shows up when trying to edit address from step 1 of checkout process. Editing address in my account simple returns the same page with all blank textboxes.

Help! I'm losing 10 customers per hour!!

[accension]

Thanks to those who may have looked at this thread, but I should've read around some more...

http://www.zen-cart.com/forum/showthread.php?t=49121

The files I updated were:

tpl_address_book_default.php
tpl_address_book_process_default.php
tpl_modules_address_book_details.php
tpl_modules_checkout_new_address.php
tpl_modules_create_account.php

I don't know exactly which one did it, but I'm sure if anyone has this problem that this will work.