I'm using the widget on WPMU, and it works... wrong.
The main site, on English, has a widget for subscribing to some list, the "/es" site has another list for Spanish users, correctly configured on the widget, and stored on the database.
On the English site, it works well, but on the Spanish site, when it makes the AJAX call it seems like the main (English) site is receiving the call, so when it gets the wp_option value for key "widget_ns_widget_mailchimp" it always retrieves the main site's one, and not the one for the "/es" site.
It doesn't make a difference to put as form action the full "/es" URL, it just always retrieve it from wp_options table.
Any guesses on that??