The point of the Default File setting is to give a file name if no file is uploaded.
On an insert page, you can set it to be a stock file, but on an update page, you would want to retain the value that is already in the database.
to accomplish that, you create a hidden element, bind the hidden element to the image column in the recordset, and bind the default file setting to the hidden element.
doing this will ensure that if no file is uploaded, it will use the existing file name that is already in the DB.
As for the code order issue, I Will log a bug.