Installed version 1.7.3 from scratch on a test site, no other plugin running and, twenty twelve theme no modification
plugins works in english though the site is installed originally in fr_FR
started to translate it to french (not fully done), took the default .po and .mo in i18n folder, copied, renamed and moved them in /wp-content/languages/plugins/
files join-my-multisite-fr_FR.mo and .po : https://dl.dropboxusercontent.com/u/33453282/jmm.zip
The changes I made do not appear, no server side caching and browser caching of (Safari and FF)
Now the question is, what am I doing wrong ?? I'm not an expert but mostly i manage to get things going.
Appreciate your time and help Mika.