Actually, to clarify my last comment, I think this can be better achieved for most users by having one list in Mailchimp and the ability on the form to select from a number of groups to be added to.
We really need this feature also for many of our clients. Being able to click on the specific list you want to subscribe to is growing in popularity in marketing campaigns.
Well… I found the problem and it was not the plugin. I double checked and realized that the term image, for whatever reason, did not update in the term interface. I tried it a second time and it works just fine.
