Thanks to all those who responded. My streaming updates seem to be working still (just checked: latest update received only 2 mins. ago). My VPS, however, is still showing the same, 160829-1. The suggestion that it is probably related to the local Avast server, and not my systems, makes sense. Guess I will wait a while to see if Avast resolves this itself, otherwise I will update to the latest versions of Avast for both systems (which I was planning to do soon anyway).
Snake: the VPS is usually updated daily, sometimes even several times a day, although there are some days when this does not happen. Thus if your system was originally showing the VPS for Aug. 29 today (when we already knew that the VPS had gone to 160831-0), chances are you were having the same problem we were having although you might not have realized it.