Subscription not displayed properly in MLM Block

The stock MLM Block view does not show subscribed mailing lists properly. When enabled with 2+ mailing lists, check boxes appear below the user's email field. Checking these boxes and clicking subscribe properly subscribes the user to the selected mailing lists. However, once subscribed, there's no indication from the check boxes which lists the user is subscribed to, the check boxes are blank.

The user can still unsubscribe from the block though, by leaving the check boxes blank and clicking the "subscribe" link again.