I just received some input from Mwb techs. They suggest I do a mbclean thing and reinstall mwb3.1. So far all seems ok. Nothing came up in terms of blocks after install and web browsing. I posted results of mbclean to their site - am awaiting response from them. I will do the delfix thing depending on what they say. I agree - I think they are very aggressive regarding ad stuff. There's just so much stuff going on -everything becomes suspect.
Of course, I still don't know what those 2 items that came thru with the Avast install are all about. Hopefully all will be cleared up. Thanks very much for your help.