Problems with Mozilla 1.1 and duplicate mail with POP account

I am running Moz 1.1 under XP. I have a pop account with flashmail. Everytime I check my mail I get all of the mail on the account - regardless if I read it or not. Eventually I get 30 - 60 duplicate emails in my inbox. I checked my account with Opera's email manager and the same problem didn't occur so it's not the server. I checked all through google but couldn't find another mention of my problem. Is this a setting problem or a bug?

Oh yeah, I don't have delete off server checked because I want to keep the messages there. But that shouldn't mean that the mail client is going to continue to dl mail that is currently in the inbox.