I've yet to get it at home, where I type in my email and password every time ... yet when I am at work and I desire to log into real quickly during a lunch break or whatever (I've got this PC set to remember me and saved my password for quicker entry while at work) I get this error quite a bit ... usually clearing the cache, or simply refreshing the page works ...

At home: Chrome (nothing saved)
At work: Internet Explorer (both user / password saved)