Well on the admin side of things username I am showing is not shown in any of our products since they dont have one. Photopost Reviewpost or Classifieds. It is only shown a cumlative total on whos online in the index for all users who have no username for display purposes. In the admin side displaying only the IP address is valid.
Don't really see this as a bug since we use the blank name to calculate who is unregistered versus registered but will consider for a later update setting an empty name in admin to use the language string for unreg users