Did recently changed the format of checkbox type fields?
Now it is not a dropdown menu with the option to tick the checkbox, but it is the complete list that is open on the field. Advantage is that is shows all options in one view, but as we have quiet longs list of options to choose from the screen has a very bad impression because you don't see any fields in your screen as the list of options fills te screen.
In my mind that was not always the case, but I'm nor sure.
