A few people have had problems not being able to talk to NPCs (completing the quest with Eglandaer and then killing him, or after talking to a ghost at the end of the Black Cove), which involved either the main characters or Madora having the exclamation mark, but leaving town through one of the north or east gates and returning would generally help.
Are you not getting a reaction at all? NPCs can assume the first couple attacks were accidental.
