IE8, Remembering Passwords, and Websites Blocking IE8

General IE8 question...

I recently used the "remember my password" function in IE8 to remember password for a number of websites.

The first time I returned to these sites, the sites blocked me!  I get messages such as "illegal attempt to access your account".

I cleared cashe, cookies, etc... (not passwords at first) and went back to the site(s) and typed them in manually.  Site still blocked me.

Cleared passwords, cookies, etc... opened new IE8 window, sites still blocked,

I switched over to my desktop (IE7), logged in (via stored passwords), and got in no problem.

The websites aren't letting me log in on the laptop now with IE8.

Anyone experience anything similar?