Can't type/click/interact in Windows 8 native apps

I haven't found a solution yet, but I can't type inside Windows 8 "metro" apps when they pop up a browser and ask me to log in. For example, in the Microsoft People app, I go to log into Facebook and a white screen opens where I'm supposed to type my email address and password in. I can't click on the fields or type anything. The only thing that I can click is the back arrow. It's as if the whole browser window just doesn't let me interact with it. Does anyone know what's wrong?