The issues with missing account login/my account on front page are caused by the amount of traffic we've been experiencing.

Also, for the future, please include browser (and version) you're using when experiencing a bug - it makes tracking it much easier.

Everyone having problems with My Account button not displaying or some page elements not being clickable on the main page: could you please try clearing browser cache / refreshing main page couple of times? We've pushed some bug fixes that should resolve this issue in IE 8/9 and in the old FF.