I had trouble when I was on 4.2.8. I've tried resetting and restarting the phone after deleting it and reinstalled it. I even made sure it was completely deleted out of itunes as well. All it does it say its loading....its frustrating.
OK, just had my girlfriend log into her account to see if it would work and it did......SO, I'm guessing the issue is with the account settings......does anyone know the proper account settings for it to work?
I see that after completing all the necessary troubleshooting, you are still experiencing problems with getting Facebook to work properly on your Apple iPhone 4. I can understand your frustrations!
I would like to recommend you reach out to the Application Developer so they can further assist in getting the application working on your device. I am including a link below with instructions and screen shots on how to Report a Problem within the application.
Let me know how this works out for you!