on page: dm_domains_admin
It shows 20 items, but has no provision to paginate or show more than that. So there is no way to maintain anything outside of the newest 20 items.
3.9.1 WP, current version of plugin, chrome browser (but same result in IE)
As a side note, it might be nice in a future version for multiple domains to allow the http://www.domain.com and domain.com entry to be made at the same time, or to allow for automatically allowing 1 to route to the other so that you don't have to have two entries for each one.