[OS X Emacs] Alt-x messed up

[Salvatore Enrico Indiogine]

Help!

I must have done something stupid on my MacBook when I tried to
configure Gnus for Email.  Probably it has nothing to do with Gnus
though.

Anyway, now in Emacs and Terminal when I press Alt-x I obtain the
squiggly equal sign, ≈.  Of course, I also get ß for Alt-s and ® for
Alt-r and so on.

Basically, I can not use the meta key anymore in Emacs or Aquamacs (or
Terminal), which of course makes it impossible for me to use Emacs.
Because, as with you all, my life runs on Emacs I am now in deep
trouble.

Any suggestions?

Thanks,
Enrico

-- 
Enrico Indiogine

Mathematics Education
Texas A&M University

Email: hindiogine at gmail.com
Skype: hindiogine
Website: http://www.coe.tamu.edu/~enrico

"Rien ne va de soi.  Rien n'est donné. Tous est construit."   Gaston
Bachelard, 1934