WNDAP350's are constantly rebooting

It's not a switch issue. These 350's are on different parts of the network with different switches and different routers. They are pinging their default gateway (all different) and for no apparent reason deciding they are not wired to the network. They turn off their radios. In about 30 seconds (give or take) they successfully ping their gateway and turn everything back on. Users who are browsing the Internet never know it's happening. Users who are connected to file servers never know the wireless went down and then came back up because they are reconnected to their resources in the background. Yes, I did a wireshark capture. The default gateways are replying. The 350's are just ignoring them. Since the problem is worse when the 350 has more associations I'm guessing it's a timing issue. I don't see jumbo frames being a factor with the 350 pinging and listening for a reply.