Facebook is constantly changing, so it might be that Facebook requires something different than what is recorded in the NC settings. But that is just a guess as I so detest Facebook and its data-mining that I placed my account in De-active mode. The FB a$$holes won't let you delete the account or I would have a long time ago.

Also, if you are using a non-rooted NC (which is what I have with the 1.1 firmware) then be aware that the NC's stock browser is really crappy. I tried using it a bit last night and it was a major pain and kept doing page reorganizations making it impossible to read an article with the text constantly being repositioned on the page. Even the B&N website cannot be displayed properly in the stock browser. So it is possible the browser might also be part of your FB problem.

The NC is great for READING in low light situations (which is why I bought it and keep it), but I don't find the other functions like web browsing to be very usable.