I know several have gone through this, but we still can't find a solution. I'm able to connect and download fine to the mac app store on my imac running snow leopard, but we recently got a macbook pro, and logged into the appstore to download the mountain lion upgrade and upgraded with no problem. Everything works fine except when trying to log into the app store now. Says "Connection Failed". I've repaired permissions, but no luck. I don't have anything else installed or running (firewall, little snitch, etc..). Just wondering if anyone else is having the same problem with the new mountain lion upgrade.