Sorry for the lack of information. I figured it was global since I have the exact same problem in 23.4 and snapshot. Maybe it's a Mac bug.
In GNU Emacs 24.3.1 (x86_64-apple-darwin12.2.0, NS apple-appkit-1187.34)
of 2013-03-14 on Johans-MacBook-Pro.local
Windowing system distributor `Apple', version 10.3.1187
Configured using:
`configure '--prefix=/usr/local/Cellar/emacs/24.3' '--without-dbus'
'--enable-locallisppath=/usr/local/share/emacs/site-lisp'
'--infodir=/usr/local/Cellar/emacs/24.3/share/info/emacs' '--with-ns'
'--disable-ns-self-contained' 'CC=cc''
Important settings:
value of $LC_CTYPE: sv_SE.UTF-8
value of $LANG: sv_SE.UTF-8
locale-coding-system: utf-8-unix
default enable-multibyte-characters: t
Major mode: Emacs-Lisp
Minor modes in effect:
tooltip-mode: t
mouse-wheel-mode: t
tool-bar-mode: t
menu-bar-mode: t
file-name-shadow-mode: t
global-font-lock-mode: t
font-lock-mode: t
auto-composition-mode: t
auto-encryption-mode: t
auto-compression-mode: t
line-number-mode: t
transient-mark-mode: t
Recent input:
ESC [ > 0 ; 9 5 ; c ESC x e m a c s TAB b u TAB ESC
C-h ESC C-h C-e DEL DEL DEL DEL DEL DEL DEL DEL DEL
DEL r e p o TAB r t TAB RET
Recent messages:
("/usr/local/Cellar/emacs/24.3/Emacs.app/Contents/MacOS/Emacs" "princ.el")
For information about GNU Emacs and the GNU system, type C-h C-a.
delete-backward-char: Text is read-only [2 times]
Making completion list...
Load-path shadows:
None found.
Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils help-mode easymenu time-date tooltip ediff-hook
vc-hooks lisp-float-type mwheel ns-win tool-bar dnd fontset image
regexp-opt fringe tabulated-list newcomment lisp-mode register page
menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core frame cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer loaddefs
button faces cus-face macroexp files text-properties overlay sha1 md5
base64 format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process ns multi-tty emacs)