I "forced" an update by opening facebook with the facebook app on my torch. Then I searched for the contact using the friends search icon. When their name showed up I clicked on it and it brought up a menu window and there is a tab that says connect to Blackberry...you click that and it tell you that this friend is not currently connected with your blackberry contact list...click "select contact" and follow prompts. Hopefully that works.
Or you could try opening facebook with the facebook app and opening the "options" in the menu. You could try clearing your cache.
Go into FB via a PC and delete the BB FB app then logout of FB on your BB. Login again on your BB and go into options and clear the cache. Next run the setup wizard again and select contact sync. Save and they should all update...
Posted from my CrackBerry at wapforums.crackberry.com