If you use WP Super Cache, make sure that “Make known users anonymous so they’re served supercached static files” in the Advanced tab is unchecked: this solved the issue for me.
Well, after wasting more time with this thing I am able to answer both:
there is no way to use it on multilanguage websites!
Maybe you can translate the admin pages (maybe) but the language files provided with the plugin seem to refer/require some “pro” files which do not exist anymore.
PLEASE make clear it is NOT compatible with WPML
Thank you
