Check your network router/firewall. These security settings could be set too high at the network level.
If you made it to this step, almost always it is that your firewall software has cookie security settings too high -- set to medium. You need to be able to accept cookies from all sites. Are you using Norton Anti-Virus? McAffee? Other? Disable it, then try again.
Are you using Zone Alarm? Zone alarm rejects 3rd party cookies by default.
Your browser needs to accept 3rd Party Cookies.
If you still cannot get in, try the following:
try using another web browser -
AOL Browsers most likely will NOT work
try using another computer
try another network if possible (like a library or work/home)