The settings on the "Security" and "Privacy" tabs are both set to the Windows default of Medium.
Whenever you sign in to a site, it places a cookie on your machine - if these settings are wrong it will not allowthis action.
Good Idea to delete cookies, files, & history while you are there.
Check your settings in Firefox as well
i use both mozilla firefox and internet explorer when i have to and when i log into anything form hotmail to ebay on either of these and then click on any icon requiring you to be logged in i am returned to a page telling me to sign in, could this be a virus or even spyware? i have done scans; (ad-aware, AVG, Spybot, Windows Defender, Registry Mechanic, CCleaner, Zone labs antispyware and trend micro pc-cillin interent security) could it be that maybe on of these has removed a file that allows me to log in? Any help with the situation would really be appreciated.