I just got my Ipad2. All is good, but from time to time, I find myself unable to type into a field because the keyboard won't pop up. It just happened in a program on the Internet, but about 4 times earlier today I've noticed it when I've returned to the iPad after being away for a few minutes. The sign in screen has a tiny lock in upper right corner, a large field to enter my password in, but no keyboard. Any thoughts? Please help.