minibuffer only frame

[David C . Nelson]

I'm using GNU Emacs 21.3.50.1 (powerpc-apple-darwin7.4.0) and I'm 
trying to setup a separate minibuffer only frame. This is something I 
used before under non-OS X Unix systems, but it doesn't seem to work 
under OS X.  Is it not supported? I cannot find anything that suggests 
it isn't supported, but when I put very simple .emacs customizations 
in, emacs comes to complete halt when starting and I have to resort to 
force quit.

For example, a .emacs consisting of only

(setq minibuffer-frame-alist  '((minibuffer . only)))
(setq initial-frame-alist '((minibuffer . nil)))

makes emacs fail to start under OS X.

Am I doing something wrong or are minibuffer only frames not supported 
under OS X?