Another sign-in issue: I cleared the iPad's cache the other day to see if the bouncing ads and "blocks" of gray would disappear. (They didn't.)
Since then, although selecting "remember me" after entering user name and password, lately I often have to enter it when returning to the site.
This morning, I got a message that I had entered an invalid user name and used 1 of 5 tries. But I noticed that "log out" was at the top of the page (not "log in"), and I actually was/am logged in.