ePMP SMs reporting incorrect Downlink RSSI infrequently.

We have noticed that a number of SMs in our network will report RSSI values significantly lower than their current values (10-20+ points lower) for periods of a few seconds before returning to their previous levels.  At first we thought it was a bug with the cnMaestro reporting, but when observing the Monitor Wireless page on the device, the downlink RSSI reading above the AP Evaluation will fluctuate, but the RSSI in the AP Evaluation table does not change.  We are running firmware 3.5.1, has anybody else experienced something similar?

when you see that fluctuation, go to monitor and wireless and check your AP evals.    check and see if you see an AP at the RSSI its changing too, on the same channel. 

we noticed this way back on 2.3.4 and attributed it to less than -29db difference between APs on the same channel.   it happened mostly with the CPE registered to a "back" AP.   

Hmm, that is very interesting.  We will monitor this on some of the regular SMs having the issue, but I found that one of the units is actually one side of a backhaul, and the only other thing it sees on the AP Eval page is another backhaul with a good ~600MHz apart from the frequencies.