What version of Zen Cart are you using? 1.5.1
Has your site been upgraded? When? From what version(s)? VPS container upgraded but not ZC.
If you've upgraded, HOW did you upgrade? (official upgrade procedure or an automated script from your hosting company?) N/A
What plugins/addons have you installed? When? If your problems are payment-related, what payment module(s) are you using? If it's shipping-related, which shipping module(s) are you using? Testimonials, Ultimate SEO, MailBeez, Wishlists, CEON URI, Google Analytics, Sitemap, Pinterest Pinit, Google Merchant Center, RSS Feed, Zen Lightbox, currency converter, Image Handler 4
If your problems are language-pack related (non-English), have you checked that all the language files are loaded and correct? N/A
HOW did you install Zen Cart? (upload via FTP and run zc_install, or a one-click install from your hosting company? (one-click installs might mean you don't have enough information about your site/server to make customizations easily)) Unknown, as programmer did this.
What version of PHP and MySQL is your server using? (See Admin->Tools->Server Info) PHP 5.3.23, MySQL 5.1.73-cll
WHEN did the problem "start"? How does that compare with other events of your hosting company, changes you've made to your site files/addons, or your admin settings, etc? After Hostgator moved us from an old VPN package to a new VPS package
Please post the contents of related "debug logs" generated by Zen Cart (wrap the content in ```
and
If this is your first store, have you tested all aspects of transactions before going live? Yes, site has been working for 5 years.
In what ways is your site customized or different from a brand new uncustomized install? Unknown
Please post your site URL* so we can take a look at it. This is especially important if you're encountering display/layout problems, so the problem can be seen directly. http://dollargraphicsdepot.com
If you're encountering problems that could be related to your server or hosting company, include the name of your hosting company (not their URL). HostGator
HAVE YOU LOOKED IN THE FAQ AREA for answers to your question? (ie: a search for your error message or what you want to edit/change, etc) Yes
Have you searched the FORUM for your error message or for answers to the question you're asking? Yes, found one article back in 2010 that did not have a final solution.