Are you running trunk? I had something similar happen on my WRT1200AC after reverting to stock and then going back to OpenWrt again. When you say it's reverting, what do you mean by that? In my case, the weirdness was that I after I had reverted to the stock firmware, when I flashed OpenWrt back onto it, the device did not reboot, and after 10 minutes or so, I had to manually restart it with the power switch. It appeared to be running in a hybrid mode (which was probably just browser-side caching) where it would give me a brief, black, Luci screen and then jump to the stock Linksys web interface. I resolved it by flashing OpenWrt via the Linksys interface again, and then immediately ssh'ing into the device and installing Luci via opkg.
Or is it that after a power cycle, you cannot ssh into the device, and it is in fact the case that the Linksys firmware and all of its settings have been restored?
Did you install Luci after flashing OpenWrt? The fact that you say your settings are retained may indicate that browser-side caching is giving you the strange phenomenon when you access it via the web interface, but that the only issue is that Luci is not yet installed. The trunk builds will not come with it. Not sure about RC3, but I doubt it.
I've not had any issues whatsoever since then (save needing to replace the mwlwifi driver with the latest from @yuhhaurlin & @kaloz.
(Last edited by fecaleagle on 30 Jul 2015, 18:05)