1. 3.6.0.0.709
2. Controller reports the APs are offline, can ping the AP sometimes, APs will for a time show up on the controller off and on, sometimes I can "catch" an AP and get it to reboot from the controller interface, If I wait too long I have to reboot them manually. Sometimes I can SSH into and AP, if I can get TOP to come up the load average is usually over 8.
3. I am on a routed(10 sites) network, running a Virtual SmartZone controller(3.6.0.0.510), I am currently running 181 APs, a mixture of 7982s and 710s.
4. No the clients can't use the AP when it becomes unresponsive.
This started happening about a month after I upgraded from 3.2.1.0.659->3.5.1.0.419 and has persisted through 3.5.1.0.419->3.5.1.0.1010 and 3.5.1.0.1010->3.6.0.0.709.
See Case 00562204 for the failed attempt by support to fix the problem.