WHat I've discovered is that if I add a Field to an entity through the Form interface, it is added with the "new" prefix; i.e., indicating it's being added to the default Solution; rather than my "ist" prefix for my Social Services Solution.
Would this be different, if as Administrator, I was assigned to the Social Services BU rather than the default?
This has caught me numerous times and then I have to go back and delete the fields out of the default and re-add them in the right solution.