I've used iChat AV with a trial version of .Mac and it works using my iSight camera. Now that the trial version has expired I registered an AIM screen name and attempted to use iChat AV again. I have a Mac Mini. When I invite my friends to videochat with me I get a message saying that I didn't respond. Man this is frustrating! I've spend hours and hours reading the tech support pages about firewalls and blocked ports, etc. But my built-in firewall is turned off! And I don't have a router. Just a cable modem. What could be wrong? Thanks in advance for any help.