Sorry for the double post but I have more information on the issue I mentioned.
It seems to happen when the menu bar is too long to fit in the window. When I am in as the Admin, and with the Calendar, etc. items in the menu bar it it is easily too large for the window width. As the window gets narrower the menu bar starts to wrap and that pushes the columns below out of position.
Could there be a version of this with a smaller menu bar?