I haven't been able to talk about this before because of all the NDA crap that is imposed on testers but I have noticed for quite a while now that WiFi roaming seems to be broken, since the early betas of 10.6.5. It also affects the 10.6.4+ build that the MacBook Airs are shipped with. I will post a bug report to Apple if anyone here can confirm this. What you need at least 2 WiFi Access points, preferably from Apple, both hooked up into a network with each other via Ethernet both of them having a WiFi open with the same SSID, same WPA-mode, same Password but different channels (please try this on the 2.4 GHz band only) any MacBook with OSX 10.6.5 configured with either an IP reservation in DHCP or static IP settings Steps to reproduce Now open a terminal and ping some internet destination. (e.g. ping www.heise.de) While pinging walk to the other Airport (or similar) base station. If the distance is far enough that Mac OS thinks it's viable to switch it will. You can option click on the WiFi signal in the menubar to check the stations Mac address or the channel to confirm the switch. Results Once the switch occurs the network breaks down and the pings stop working. It either has timeouts or even routing problems. It will not recover from this in most cases even when you walk back to the original station until you manually disable and reenable the Airport on your MacBook. I have personally confirmed this with several MacBooks and on 2 Airport Expresses + a 3rd Party WiFi Access point. It used to work between all of them in 10.6.4. Please confirm this for me, so I can send a bug report. Thanks!