It would appear that what we have here is a simple "glitch" in Avast's determination of what is, or isn't, up-to-date as it seeks versions of software for the Software Updater.
Now, without me doing anything other than clicking on the Software Updater again (hours later than my initial report above), I get:

And, I failed to mention before that this isn't the first time that on one day it will show that Firefox (JUST Firefox) needs updating (when it didn't) and on the next day, show it being up-to date.
So, with all things considered, this is a minor event that doesn't need further scrutiny relative to my own Avast Program, unless the powers that be decide this is worth further investigation in order to find a cause and ultimately a solution that will help others possibly having the same thing happen to their own Avast 2015.
If, and when, it occurs again that Avast tells me Firefox is not up-to-date, I'll click on that info Icon (
i ) and see what version it "thinks" I have and post it back here.
Thanks!
Gene
