Ahh to joy of being wrong! Found the one setting that somehow was changed - the one that sets "Scale Sensitive" in the lib parts dialog. All the more reason that settings should be consistent and when one critical setting changes - all the other settings of the same thing follow.
Thanks Karl - I did that routine and it worked for a while. I think that somehow the settings are reverting to a previous one - why is not clear to me but by watching the selection process more closely I may hit upon the failings of doing the wrong thing. This particular difficulty has made the selection process very time consuming and requires more diligence in mousing and shift keying. It showed up while trying to get the windows and doors to all agree.