That is usually a problem with corrupted cookies.

Clear the cache and the cookies from sites that cause problems.

• "Clear the Cache": Tools > Options > Advanced > Network > Offline Storage (Cache): "Clear Now"
• "Remove the Cookies" from sites causing problems: Tools > Options > Privacy > Cookies: "Show Cookies"

sorry this did not help, i can access the site using user name and password but when i try to access content it comes up as 400Bad Request