[OS X Emacs] problem C-x C-f 'ing a file in two windows

[xioni]

Hello,

Something has changed to produce an undesirable behavior. If anyone can suggest how to revert back, it would be greatly appreciated.

It used to be that if I had a file open in a buffer in one aquamacs window, that if i focused on another aquamacs window and tried C-x C-f that file in the new window it would load it there too.  Currently it is no longer doing that (unless I select 'open file' from the file menu).  Instead C-x C-f sends me back to the original window where the file is loaded.  I am not sure how this even changed.  

Any ideas?

Thanks,

sf