[OS X Emacs] Aquamacs: Minifbuffer strangeness when changing default font

[Jeppe Nejsum Madsen]

Hi,

If I add 

(set-default-font "-apple-Inconsolata-medium-normal-normal-*-14-*-*-*-m-0-iso10646-1")

to Preferences.el, the default font doesn't seem to change, but instead
the Minibuffer font seem to be changed. Whenever something is displayed
in the minibuffer, it is enlarged to show the larger font and when the
text disappears, the mini buffer is shrinked, causing an annoying
flicker

So,

1) How can I globally change the font?
2) How to avoid the minibuffer flicker?

/Jeppe