Ok, on the clean install test version, I changed the 'Form Display' text to something else, and yep, the field disapairs from the admin add forms. Tried renaming back to Add_Date and the field wont return as it remains hidden. The 'Form Display' shouldn't effect this - perhaps this is a bug?
~ ERASER
Free JavaScripts @ Insight Eye
~ ERASER
Free JavaScripts @ Insight Eye