log out – can’t log back in – users and admin

Every time I log out of my blog, I can’t log back in – there’s no error message, but the login page just pops back up as it was. This occurs whether I use my admin name and password and on all users. It also occurs in both Firefox and IE.

I have to have a new password emailed to me every time. Even if I’m logged in as the admin in Firefox and I change the user’s password there (in Edit User), I can’t then log in as that user in IE. Only a new, WP-generated password will work.

Very frustrating!