Thanks for your reply Dr Byte
Yes indeed I found the auto logon thread, in the past few days I've used the contrib, but there seems to be probs 'for me' with various aspects as far as my experience as a user running it goes, with a dot com domain.
I wonder if its a possibility to store the cookie as data in the database, that's to define whether this cart user is an auto logon user, or not. The damn browsers seem to have got so particular about the domain name format for cookie path, and each browser's doing different checks.
Plus I suspect there are issues about exactly when the server updates session variables to \tmp disc file, inside a page creation process which assigns new session variable values within it, then we assume the rest of the page php code will see the session values update immediately.
my brain hurts.. but a transparent auto log on would be a useful zencart feature.. if you want to help out, see my 3 recent thread posts in that auto logon contrib's thread.. i'm feeling my way over there..