Quote Originally Posted by sweetikins View Post
When i go to the store and add products to the cart and click on checkout it asks me to log in, once i have done that i get a time_out.php page with the error message.
After that happens, what's in their cart at that stage?
Do you know whether the same issue occurs if someone had something in their cart from a previous shopping session, but had logged out and never completed checkout with the items in their cart? Does it display the shopping_cart page again with a note that their cart contents have been merged? Or does the "whoops" message display before that can happen?

Quote Originally Posted by sweetikins View Post
i get a time_out.php page
Zen Cart doesn't use "time_out.php" unless perhaps you're using some addon that rewrites URLs. Do you have such an addon installed?