Well if connection is not reliable then just create separate BES with separate SQL /msde db on your site. Try though connecting both to a same and see if it works. If it does not then do copying of db and removing old/first BES from second DB. You should then remove users/ second BES from old/first db.
Depending how many users you are adding to a new server from old one it might be easier to remove them from old and re-activate them on new.