CentOS - Aug 2006 - Lang packs (extensions) not found with firefox-1.5.0.5-0.el4.1.centos4 ?

Hello,

  with CentOS 4.3 (i386), after updating firefox to 1.5 from update repo, I 
can't get it to have menu in my native language (french), altough french 
language pack appears in extension list.
  I've tried many things, like moving it on top/down, disabling/removing
other
languages packs, creating a fresh new user, and reinstalling firefox, to no 
avail (yes, I restarted firefox between these attempts).
I also searched in upstream's bugzilla, and didn't find any issue for
v4 & firefox...

  Finally, launching firefox through strace, I find that it searches for
/usr/lib/firefox-1.5.0.5/chrome/fr-FR.jar
and can't find it, since french lang pack seems to be
/usr/lib/firefox-1.5.0.5/extensions/langpack-fr at
firefox.mozilla.org/chrome/fr.jar

I filed the issue in CentOS bugtracker:
http://bugs.centos.org/view.php?id=1442

PS: if that matters, I'm using KDE from kde-redhat repo...