Presidents' letter against UCU boycott call?

I've been following the recent discussions on Harry's Place and Engage about the arguments on the UCU activists' list with interest. And I've started to wonder what response there was to the UCU's renewed boycott call. Was there another call by U.S. university and college presidents to denounce the UCU motion? I don't remember that there was. (This is relevant to something I'm working on now). If any of my (not so numerous) readers know the answer to this, please let me know.