I bought a MACBook air last year and connected flawlessly to wifi until a few months ago. I never lost the wifi-signal, however, would lose the ability to PING the default gateway of the wifi connected networks. The only work around was to disable/enable wifi or power cycle laptop. After multiple phone calls to support and replacement of the wifi controller, the problem continues to plague me while using the MACBook anywhere. My case was escalated to corporate and they advised me they could do nothing else - my problem was "environmental" - wow, thanks for the support Apple. I have a flaky MacBook Air and you have convinced me that you do not stand behind your product or customer. Has anyone else had intermittent wifi issues on their MacBook air ? If so, what was the resolution?