Im sure a reboot will recover the S/N as this will recover the bins that have been marked as bad, but the S/N will only drop again in the evening as the bins are again marked as bad. Looking at my bin/tone loading it is very clear that areas where the s/n drops at night result in those bins being disabled. On other routers, the bins come back into play when the S/N recovers. You can see this on MYDSLwebstats> prior to using the Netgear on Friday evening, you can see my S/N drops in the evening and recovers during the early hours - by around 1 - 1.5 dB. However with the Netgear, the S/N dropped as usual but did not recover in the early hours resulting in a fairly flat line since Saturday.
I may power off for 30 mins and then power back on when i get home......
Netgear need to be advised to look at Bin loading and bit swapping algorithms.