Double opt-in does NOT add user to Mail Chimps List

I have a top bar and a sidebar widget using the MailChimp for WP plugin.

I want to have double opt-in enabled. However when i do this it doesn’t add the users to the list once i go through the confirmation email process.

Enter my email > Confirm sub page > get confirmation email > subscribed > Check my list in MailChimp = not added?

When i have double opt in disabled, i do not get any of the confirmation emails, but it DOES add to the list?

Any help?