The 1970 date on files copied to the dbox is nothing unusual, it just means your box is receiving no services yet! Follow pt-1's advice for a dual box scenario, and put the second 'iffy' box onto the same connection as the first 'good' box- ie: a swap-out.
Then just apply a bit of lateral thinking. If it works- the 'other' cabling / splitters infrastructure is suspect. Connecting your good box to this should verify this is the case. If the iffy box still won't work on a known-good feed- then it points to a knackered (or butchered!) tuner can.
Cheers- AL
