My network issues with my iMac is really driving me nuts. I'm able to open two or three tabs in Chrome/Safari without any issues, but when I try to open more connections the response times are 30 seconds to several minutes. This occurs both on wifi and ethernet. * I'm running the latest version of Mountain Lion with default network settings (DHCP). * I've replaced the router but the problems are still there. * I have a MacBook 13" Retina on the same network, with the same ML version without any network issues at all. * I've tried to change the MTU size. * I'm not running a torrent client or similar applications. Grateful for all suggestions.