airport extreme MD031LL/A intermittent freeze / lockup

I have exact same problem. So far unsuccessful in troubleshooting. Let me know if you find anything relevant...

I am having the same issue with both AirPort Extreme and AirPort Express units connected together in a roaming network. I have 10 devices on the network and every week or so I lose 3 or 4 of them to the freezing effect where the green light is solid but there is no network connection to the device. I check AirPort Utility when people begin to complain about not being connected and will see which devices have frozen and then a power-cycle is needed to fix it. Everything has the latest firmware 7.6.3 and many of the units were purchased a couple of weeks ago so they are all in working order. I am using a high-quality Cisco Router and Netgear switches for the overall network topology and all AirPorts are connected as bridged access points with fixed IP addresses via CAT5 cable.

I found a number of articles dating back to 2006 about this happening!! I can't believe that it hasn't been resolved in some way. Any help would be appreciated. Thanks.

Hey, just wanted to give you guys an update. I seem to resolve the problem by shutting my network down completely, only allowing in one device at a time. In my case, a network printer's IP was not getting updated in DHCP table and the router would hand the same IP number to another device. I can not explain the symptoms - makes no sense with all green lights, etc... However, I was able to replicate the issue several times, before finally taking the printer off network. Not a hiccup since...

I've had this problem for a couple months now, and took a stab in the dark after I noticed a pop-up about using an IP address that was already in use. This reminded me of the corrupted LAN cache problems, for which the solution was to shut down every Apple device at the same time. We did that and the AirPort Express Base Station has been fine for over forty hours (when it had been locking up at least once a day, sometimes thrice).

Tentative conclusion: Something in the shared cache gets corrupted, and as long as any device still has it, it will continue to propagate to any (Apple) machine that joins the network. Sometimes this corrupted data causes previously recognized machines to be forced to use new names (MyMac (2)), and sometimes the router keeps its light on but actually goes away to contemplate its navel.

Short answer: Shutdown (not sleep!) all entities at once, then turn them on again.