So something strange. Usually I am at work or not-home middle of the days, but with the holidays, I have found myself at home and using the spare bedroom (due to ongoing renovations) where we have our 4642. For the last 3x days in a row at approx. 3:45 p.m. the unit hard-reboots itself (doesn't matter if the unit is in use or in standby). FWIW we have WHPVR (8642 + 9865). I checked the firmware page and doesn't show any changes to any ROM dates. After the box LOADs and comes back online/can be used, the front display will say its trying to download but nothing will happen.
On channel 1, Power (dBmV) of 0 and a SNR of 36
On channel 3, Power (dBmV) of 2 and a SNR of 38
On channel 8, Power (dBmV) of 2 and a SNR of 37
So I do not think it is signal related, since I appear to be in the sweet range.
CM4228, CM4220HD, Samsung LNT3242H, AccessHD DTA1080D, RCA DTA800, CM7775, Samsung DTB-H260F, Samsung LN40B750