We have two kinds of bugs that have happened over login issues. One was a fault of our own, and the other is a technical issues we're still trying to determine. What I've noticed is that many people from outside U.S. encounter the problem the most. So, if you wouldn't mind, please report your location and browser in this topic.
Location: (Country only)
Browsers used: (IE, FF, Chrome, Opera, Safari)
Band-aid fix until this is resolved, you'll have to change your password; sometimes more than a couple of times in a month. We do apologize for the problem as we continue to determine a solution.