Our wireless uses 802.1x authentication against Microsoft's RADIUS implementation in NPS. Macs don't connect to the network until someone's logged into them, so I got this error message until I plugged in. Does mean you can't really use domain accounts on a Mac laptop, though, unless we set up an SSID that uses a static key, which I don't really want to do, or someone can tell me how to make the mac use the AD computer account info when no one's logged into it.