Outlook Ex, email, reset to LOCALHOST

tools / accounts / select account, then properties / servers / incoming mail (pop3)line, always changes itself from what it needs to be set as to LOCALHOST. I have to go in and reset it each time I shut down Outlook Express or Outlook. And it adds the setting that needs to be in the incoming mail line to the (account name) line, along with whatever is already there. It is this way everytime I shut down and restart.