Comment 29 for bug 614742

So:
 * go to facebook -> account -> privacy settings -> applications and websites settings -> "Remove unwanted or spammy applications" -> remove Gwibber
 * launch gwibber, manage accounts, add facebook, enter your login (email address works here)/password to authorize Gwibber as if it was the first time
 * the "Add" button does *not* appear yet
 * close the Gwibber's account window, open it again and redo the facebook connexion process
 * the "Add" button appears and it works finally well

Yes this finally worked for me in Ubuntu 10.10