A Couple of Problems

I've been experiencing a couple of problems lately with my site.

1. I cannot log into my site at all (even using the utilties to get into my admin panel) using Mozilla Firefox, but it will log me in on Internet Explorer 7. Although it logs me on on IE7, it will also log me out sporadically while using it, for no reason at all (it also happens when I refresh my page).

2. Forum icons remain showing new posts, when they have already been checked. I have to log out and back in for it to show the No New Posts image. I have tried using my utilities to remove HTML errors, and they seem to have done nothing to help.

The first solution I see would be trying trying to delete your browser's cache and temporary internet files.