I’m about to try a reinstallation due to the intermittent behaviour shield problem (sometimes failing at startup)…I’ve already tried a repair.
Would you kindly tell me if I should uninstall Avast through Add / Remove Programs or use Avast Uninstall Utility?
Do both and use the off-line installer of the latest avast version to install again.
Thanks a lot Eddy. 
Update - I did that…
Unfortunately Behaviour Shield failed to start after the reinstallation. Odd that this is not always the case at boot up. Hopefully the problem will be solved with next version…