Lodged a request with customer support on the problem described above and had a reply within two days ... excellent!
However, having followed the recommended procedure I attempted to run Grime Fighter, only to find it had disappeared.
I attempted to reply directly to RP at Avast who had said "If you need further assistance, don't hesitate to contact me back." but got the following reply:
"in order to better assist you we have implemented a new support/customer care system. We therefore kindly request that you visit
http://www.avast.com/support avast! Customer and Technical Support and resubmit your question."
Sorry, no desire to go through the system again.
I'm not a computer nerd and I'm not interested in spending large amounts of time fiddling around to fix a system that appears to be unstable/not well developed.
Yes, I have a subscription to Grime Fighter with more than 6 months still to go but forget it! I'm not interested in GF or money back when it's giving me the feeling it could cause trouble rather than fix it