Backup and let's go over it again.
You have a
blackberry data plan.
The blackberry browser, push email, and BBM work.
Other apps do not work? What else does work, and what doesn't work, exactly (besides blackberry appworld)? ... Appworld is flakey, it seems. If that's what you are having trouble with, then all I can advise is search and see what others have figured out. Other RIM branded apps should work, regardless of which version of 5.0 you are running. If you are having trouble with third-party apps, then that's another matter.
There's only one other thing I know of for you to try, based on what I understand, and that is to re-send service books. See
How do I resend my service books? - BlackBerryFAQ.
Posted via BlackBerryForums.com Mobile