1054 Unknown column 'COWOA_account' in 'where clause' -- when submitting billing info

Greetings-

I'm using V1.3.8a of Zen Cart. The hosting company "Host 99" installed the latest version (I'm assuming) including the security patch.
When testing the billing info page and then submitting it, it returns with:
1054 Unknown column 'COWOA_account' in 'where clause'
in:
[select count(*) as total from zen_customers where customers_email_address = '[email protected]' and COWOA_account != 1].

I found another thread here stating the same problem but it didn't quite answer my question. I would like to know if the Checkout Without Account can simply be removed from the page. Will doing this resolve my issue? If so, it appears I need some directions as to how to install/remove add-ons. I'm also not interested in using Newsletter but that doesn't appear to be installed anyway.

http://oregonwildberries.com/index.php?main_page=login

Many thanks.

Richard