I don't have that problem Bob, and to tell the truth, never had it. I am sure, there must be something inside the code that controls the opening of that window... since you don't have similar problems with any other part of avast! GUI, I am sure Alwil guys should be able to check that particular code and compare/find the differences between that one and few other things.
I know how annoying that could be even if it's just about that ABOUT AVAST!... panel. I'm also sure there are some other people with similar problems, it's just they never paid attention to that. Maybe it's coded to use something that's usually always installed inside the OS by default, and maybe (just a possibility) you don't have it installed on your system, I have no clue... but certainly we should get some answers from Alwil coders.
Alwil ?