I have just set up my new iBook with my broadband ADSL connection using airport express and a Zoom X3 modem. It works fine with mail, safari, and text chats using iChat. BUT.. I can't make video or audio chats work. I can get as far as issuing or receiving an invitation to chat, but then it says something like "the other user did not respond". My brother is getting similar messages at the other end. I have turned off the OS X firewall, and so I think this is something to do with the firewall in the modem. I tried to disable that, open ports, and set up a DMZ or something, but I didn't really understand what I was doing, and couldn't get it to work. Can anyone who has got this modem advise me on how to disable the firewall in easy steps please? Thanks.