Have cable broadband modem (charter/Abit)with router for 2 computers e-machine w/vista and I-mac .I can't connect to internet with both computers at the same time only one at a time.I can connect to 1 computer after reboot of modem both will connect but not at the same time,says can't find server.Is this Charter or Vista,software problem. Have used 2 routers Linksys and generic both have same results.