@AaronClark - Are you 100% certain this is a field added by you (or your client)? Are there delete buttons for any custom fields? To test, create a dummy field on Company entity. Click the field and check if Delete is there.
If the delete button shows up, something odd has happened to your database. If it doesn't show up, we can still resolve the problem but it is very unusual to say the least.
BTW - the resolution is:
1. Go into MS SQL.
2. Pull up the Custom_Edits table.
3. Find the field in question (use the colp_colname field).
4. Set Colp_CanDelete = 'Y'.
That should work.