POP service won't authenticate

I get the following message when I connect to one of my POP accounts "Authentication failure: kindly change the Mail settings and re-enable auto fetch". The problem is I checked the Mail settings they are correct. I can still use the SMTP feature which uses the same user name and password to authenticate to send mail as the POP service uses to login. So it looks as if the POP settings are corrupt. My other email profiles are working fine. Anyone have any ideas on how to fix this problem? Thanks, Mike Failure: Kindly change the Mail settings and re-enable auto fetch Authentication Failure: Kindly change the Mail settings and re-enable auto fetch