IE 5.5 Webpage info box autocomplete.

In Win 98SE, running IE 5.5, when I visit a page that has a login box, as in the hotmail page, and I have logged in before, Windows remembers what I have typed and if I click on the box (like the username box) I get a choice of things previously typed. Nice feature, but recently the choices I have are corrupted, but not consistantly… only once in a while. I have searched the registry for these choices but found nothing. Where is this information stored and how can I either delete or correct it?