I thought i was the only one. My router factory reset itself. I thought someone hacked my router and reset it. So we should not reboot the router at this time? It happened after i updated to the latest firmware V1.0.2.74.4SF. The ones before that were ok. Anyone knows the resolution yet?
For me, I was running V1.0.2.74.1SF when it happened, and I used the opportunity to upgrade to V1.0.2.74.4SF--so at least in my case it could not be due to V1.0.2.74.4SF. But I feel bad mentioning these things together because some people might not read on, and might take it wrong. But to be clear, I do not think it has anything to do with the firmware that is used--it is a hardware problem--and even though we have several reports, I suspect it is just a matter of coincidence. Indeed, as I searched more, I found abundant references about similar happenings with other Netgear routers, not only the R7800. Perhaps Netgear uses a lower quality brand of flash vs. other manufacturers (like Asus?), or maybe they treat the NVRAM differently by writing to it more frequently? I don't know--this is all speculation on my part.
Regarding rebooting your router, up to you. In my case, if I do not reboot, it maintains the settings. In my case, it takes about ~15 minutes to get things where I want it because there are lengthy pauses everytime you apply a change. If settings could be saved and restored, that would really help mitigate things, and almost make this situation tolerable. But at least in my case, the save and restore of settings does not seem to work with the NVRAM gimped...