As a follow up:
I set the Live View on the page to which the login form data is sent (called validate.php) using ALL the form values, with the POST method. The page redirects as it should, but I'm not logged in (no session created).
What am I doing wrong? Could it be that the referrer is rejected? When I access the validate.php page from my browser's address field, I don't get any referrer errors, just "Invalid username or password" message.
All I'm trying to do is to open admin session for DW Live View
Since user authentication requires SESSION VARIABLES, I'm skeptical that you will be able to get to those pages in DW. When I build such things, I put the authentication on as the very last step, after all the layout/Live view issues have been dealt with.