Just to confirm this has not worked.
I downloaded and ran the VPS file from http://files.avast.com/iavs5x/vpsupd.exe but it resulted in a simple message:
‘VPS database is already up to date.’
So, no further forward and I’m very reluctant to commit to the often time-consuming, not to say hazardous process of uninstall/ re-install, even though no other AV program has ever been installed on this computer.
My feeling is that Avast issued something in an automatic update in early August 2013 that has caused this malfunction and I would like to think they would feel bound to put it right.