I guess I just don't know how Avast's build numbers work and when, how often, and/or why they change. It's also not something I was paying attention to before the last week or so, so I don't really even have a frame of reference for whether this is "normal." I also remember you (DavidR) saying that yours went from 765 to 766 to 768 in between computer shutdowns and boot-ups.
Wasn't me, as chris.. mentioned.
However, the build numbers are more detailed than the simple program version number.
Every change to a program is incorporated into a build version number, e.g minor changes or fixes to the program. The build number is more useful to Avast as every change to to the program is assigned to a build number. There could be multiple changes within a build number, but Avast knows what those changes are.
For the most part users are mainly interested in the program version, outside of issues like this when related to the Bank Mode issue, where the fix would have had an assigned build number. More relevant when a new update/build number breaks something Bank Mode, hopefully Avast can pin down the problem in that build number to break it again.
Note I haven't got 76
9 as I don't often restart this laptop, so still on 768 as in my signature.