1. Are your virus definitions up to date?

  2. Are you using the current (new) version of Avast (6.0.1125)? Did you upgrade or do a clean install?

  3. If yes to the above questions, is your firewall (FW) blocking anything related to Avast?

  4. If no to question 3, reset your setting for Avast in your FW. Does this fix your problem?

  5. Do you have your Avast settings set for dial-up?