Sorry you're having troubles with the site! Can you please try clearing your browsing cache to see if that helps at all? Also, are you logging in via the main page or the login page?
Main page: http://www.chess.com
Login page: http://www.chess.com/login
on google chrome every few days when i type in chess.com onto chrome, put in my username and password and click login it blinks and brings me back to chess.com (not logged in), i always close chrome and when i reopen it, it works regular for a few days till it happens again. Its a minor problem, but its annoying!