Not sure if this ever worked, or if it worked in earlier releases and is simply broken in 3.7
However, so far none of my efforts to process invoices through this plug-in have succeeded. (You can read my support request on this plug-in to get the details.
Suffice to say that it just plain doesn't work as advertised. A bit frustrating is although the marketing information has been translated into English, all the support documentation is still only in Portugese. -- great if I'm a Victoria's Secret Brazilian supermodel but otherwise completely useless.
--enough of the rant: I'll delete this plug-in, clean up my WP install, and move on to finding a performing plug-in.