I have noticed that frames does not behave the same wrt. iconification
as under X11 (at least not under OSX) for emacs 23. 

Suppose you have two frames (C-x 5 2), iconify one (M-x iconify-frame)
and leave the other visible on the screen. If you then call
`other-frame' (C-x 5 o) then under X11 nothing happens (you select the
same frame) but under OSX, the previously iconified frame will get
de-iconified and selected. In other words, under X11 'other-frame'
ignores iconified frames whereas under OSX all frames are considered
equally visible.

Apparently (to my naive reading of the code in src/nsterm.m) the problem
is exactly that the frame parameters of 'visible' and 'iconified' are
not updated as the frame is manipulated.

Below is a small patch against nsterm.m which improves on the problem
(i.e. iconified frames will again be ignored by 'other-frame') in the
sense that frames behave correctly when de-/iconified from within
Emacs. It will however not cure the problem if the frame is iconified
from the outside (i.e. by clicking in the yellow button), then the frame
parameters will still be wrong and thusly iconified windows will pop up.

I know too little about NS/Cocoa to know how to do a proper fix, but at
least we will get a good bit futher towards a solution and at least for
me that routinely uses many frames, it will be very usefull.

The diff should apply cleanly against a recent version of the repository.

                              -- Christian