Normally, when I want to log in, I click on the "Login" button near the top of the page without filling in my information. This presents me with a page complaining that I did not supply my log-in information. If I then fill in my log-in information, I now get a message that there was an error: and that I should wait 45 seconds before trying again.
If instead, I fill in my login information with the mini form next to the login button (like a 'normal' person?), it appears to work every time. The other day, the login with the intermediate page failed at least 3 times. Today it failed once before I gave up on it.
One awkward thing about this bug is that there is no clear way to report it until you find the work-around
