Using the 1.0.1 version of the plugin and WordPress 3.4.1
The plugin appears to work on the site (settings, api key entry, form embedding and submit/confirm functions), but no confirmation emails are generated. Additionally, the form replies "Member not added". The user is added to emma as a user pending confirmation, but with no confirmation email generated, the user cannot complete the process.
Looks like the plugin is not properly queueing a confirmation email from emma.