I've had a problem with some wwf sites. The characteristics of the problem have been.
- Go to a New site and register
- Go back to the new site in another session later and get the cookie problem.
- Use the IE option to "Delete Cookies"
- Look in the Temp folder and find that all cookies were not deleted for the site.
- Manually delete the cookies.
- Go to the site and login
- Never see the problem again for that site.
Now, whenever I see the problem, I just shut down the browsers, manually delete the cookies, and go back and login. works for me, and I never have a problem with the site again.