Thanks Bob and David,
As it was still not right on my PC, I shut down malewarebytes completely (so it doesn't start with Windows), rebooted, did the full uninstall of Avast, cleanout (Avastclear.exe and RajZor's Cleanup), reboot, Clean install of 2014.9.0.2012
Had some difficulty getting AvastClear to work - would ask to run in safe mode, reboot but then ask to run in safe mode again, reboot, ask to run in safemode. Resolved by turning off Avast self protection.
New installation has all default ex factory settings, and has the same two problems as I've reported previously, the missing bit at the top of the Firefox AOS panel (best demonstrated at
http://www.asx.com.au), and the lack of any ticks (web rep) anywhere. I've also just noticed that it thinks no one is trying to track me at all, regardless of how many sites I visit, so I suspect that doesn't work either.
It's 1:43am so I'll leave this at the moment and reinstall 2014.9.0.2011 again and see what that does. The web rep and anti-tracking used to work, and I don't think I had the missing bit in the panel, but I haven't had AOS installed for while, so worth a recheck.