You are totally right, DavidR, it is a useless thing to do a manual program update when there is nothing to update.
I mentioned this only for the "avast! curiosity cabinet" and on purpose did not adress it to "pk".
There is the avast! team using some of their brain power to cover some issue and succeeded; and here comes some user hitting a "useless" button and an avast! integrity check is stealing the above mentioned success!
By the way the manual def update does not "steal" any dll's, it's only manual program update!