Untranslated gettext UTF-8 strings and different platforms

Hello,

I have two servers, one Apache 1.3.x running on Mac OS X and one Apache 
2.x running on Debian, both with PHP 5.1.x compiled with gettext.

On the Mac OS X server, everything is working correctly. I get the 
right translations in the right encodings. But on the Debian server, 
the msgids which are not strictly US-ASCII remain untranslated.

I use the following code to localize my website, which is entirely in 
UTF-8 (all the PHP files are in UTF-8, and the messages file are 
encoded as UTF-8) :

putenv("LANG=$language");
putenv("LC_ALL=$language");
setlocale(LC_ALL, $language);

$domain = 'messages';
bindtextdomain($domain, "./locale");
bind_textdomain_codeset($domain,"UTF-8");
textdomain($domain);


where "language" is either (fr_FR.utf8 or en_GB.utf8) on my Debian 
host, or (fr_FR.UTF-8 or en_GB.UTF-8) on my OS X host, to match the 
available locales.

If I've understood correctly the docs, gettext does a binary comparison 
between the msgids, so if the files are in the same encoding, the 
lookup should not fail. Does anyone know what differences between the 
two platforms causes these different behaviours ? Or does anyone see 
any bug in the code ?

Thank you in advance,

-- 
Thomas Deniau