Puzzling issue w/ Facebook website

So I loaded up facebook.com the first couple nights w/ my iPad, and everything was perfect. I was wondering whether or not the chat functionality of the site would load properly, and happily for me it did. I was able to chat on facebook.com the same way I do on my Firefox browser on the desktop PC.

But, the last couple of days I've tried it, the chat functionality does not show up on the screen at all. Where did it go? Why would it work the first few days, but then not at all after that? And I'm not using the app (yet) because 1) There is no proper iPad facebook app yet, and 2) if I do it through the browser, I can still browse around the web in another window and switch back and forth. I'm just trying to figure out why it was there in the beginning, but gone now.