[Plugin: MailChimp List Subscribe Form] Groups aren't carrying over

I’ve been using cforms II and updating my lists manually, but figured using the Mailchimp widget for my class alert list would be much more efficient, especially since visitors can select their groups, making life so much much easier.

But the problem is, the groups aren’t carrying over. I get names, emails and then a big blank spot for my groups (I’m using checkboxes). I tried it myself, and it’s not giving an error message, it’s just ignoring the interest groups entirely.

Any ideas? As much as I like the auto update of my list, I don’t have any clue what groups they’re selecting, so I don’t know which newsletter to send them, which is a huge problem.