tab tamer is a great module. all the default drupal tabs along the top really throw off my css. so i found this great mod to help. tab tamer allows you very granular control over the system generated tabs.
When I chose “hidden” for the tab in tab tamer for the node/edit field the variant for node add/edit disabled itself. after testing a few things, i was able to get it working again by setting that specific tab to hidden.