There are no problems here, besides a little visual glitch in the sharedlistctrl with korean, Some messages are not translated (e.g. debug, connection notices) at all, but everything else is displayed fine.
I enabled the locales in /etc/locale.gen and ran locale-gen to create them (the Arch way) and then I simply selected the language in the preferences and restarted aMule.
Software I use: glibc 2.7, wxgtk 2.8.4, gtk 2.12.1, aMule r7675 (i.e. last updated today 3:30am UTC+1)