DavidR
7
As I mentioned there are a few topics relating to similar issues with the latest version of avast on XP and Vista systems.
I don’t know if they have this recorded as a bug (and working on it) or not. The problem as I see it that it isn’t consistent over all XP and Vista systems (or web sites), so trying to pin it down probably won’t be easy.
For now I would leave https enabled (to give better protection) and only disable it on sites that you have problems with. Unless you know the specific site with the problem, disabling the https or web shield does carry a risk.