Field box disappears on save

When I edit an entry, the custom fields aren’t there. If I open the screen options, they are checked to show. If I uncheck and recheck them, they’ll appear. I can make a change but as soon as I click update they disappear again and I have to uncheck and recheck under screen options to make them appear. Anything I do change is saved though. This happens on a new entry as well. Thanks in advance.

http://wordpress.org/extend/plugins/advanced-custom-fields/