Attention Line Required - Broken

For many accounts, we have cost center set up in the Customer Attention field. The users are set up with a check out setting that requires them to select an attention line. This is currently broken and users can submit orders without selecting an attention line. The only way to get this to work is to change the checkout setting to require a short po#. However, this is confusing to users that don't use PO #. We can relabel the field, but that then requires them to type additional information that is not necessary. Also, once I do select an attention line, the next order defaults to that attention line, even though the user is set up without an attention line default.