We just rolled live on a custom cart for which we spent 3 months migrating and customizing the front end. Front end. No customizations to the Admin except as below (CAPTCHA). Now that we are live we are receiving what we think is customer spam. Every day we receive many "new customers" sometimes hundreds with legitimate sounding names but with the caveat that the records are deficient in such a way that we can see the following PHP errors in admin/customers.php:

Code:
Warning: array_merge() [function.array-merge]: Argument #1 is not an array in /var/www/html/admin/customers.php on line 1099
Warning: array_merge() [function.array-merge]: Argument #2 is not an array in /var/www/html/admin/customers.php on line 1101
Warning: reset() [function.reset]: Passed variable is not an array or object in /var/www/html/admin/includes/classes/object_info.php on line 29
Warning: Variable passed to each() is not an array or object in /var/www/html/admin/includes/classes/object_info.php on line 30
Real customers (our testing) show up fine, and do not throw these dependency errors.

Here is an odd thing: Going to the database, we see that looking at all the tables mentioned in select statements in /admin/customers.php: customers, email_archive (yes, turned on), address_book, customers_info, coupon_gv_customer, reviews (turned off), group_pricing and zones, we see no reference to the names that appear in our "New Customers" list in Admin Home. Clicking these generates the errors. If we sign up nicely in a test, we see the information show up fine in the first 3 tables.

I have checked the FAQs and searched the terms related to "customer spam" "fake customers" and related terms. Search results are nil.

I chose Business Issues > Fraud Prevention, hopefully correctly, please re-route if incorrect.

Using Zen Cart 1.3.8a at Westhost; Linux, Apache 2, PHP: 5.2.92 MySQL 5.0.67. It was a default installation. Because of deep customizations, we have refused upgrades.

CAPTCHA: We first installed this: http://www.zen-cart.com/forum/showthread.php?t=42780 But that didn't seem to work very well for us, so we tried our best to uninstall.

Then we installed this: http://www.zen-cart.com/index.php?ma...oducts_id=1306

And it seems to be functioning fine for New Account Registrations. This does not touch the Contact Us form. Smoother installation if I may say so.

We are sifting through a bunch of noise to collect our real orders. Advice? Thanks much.