Motorola Droid :: Why Do Deleted Emails On It Keep Reappearing As New

I have two Time Warner RoadRunner email addresses set up on my Droid. Inexplicably, sometimes when I delete emails, they reappear as a new incoming email either the same day or even many days after deletion.Sometimes, I can delete the same email multiple times before it stops reappearing.I do not want to change the setting on my RoadRunner set-up to "delete after reading" because then I will not see these emails when I get home from work and login on my laptop or my desktop.Somehow, the Droid cannot seem to distinguish that an email has already been read and deleted.