I have a friend running 1.1.4 w/ a ziphone jailbreak who installed Twinkle and is getting an 'Authentication error' when trying to login to Twitter on it. She changed her password on twitter as part of her diagnostics, as well as uninstalled it 3x and did the full restore rigamorale back to scratch, still no joy.
She can log into Twitter on her PC fine, it's just Twinkle that's not working. Good question, though! It's working 90% on mine (occasional dropped posts, doesn't consistently show my history, etc) but about 0% on hers.