I'm testing the Web-based self checkout module. When you enter the login/password of a patron without the self check permission, there is a message Access denied Sorry, the system doesn't think you have permission to access this page. With a link Log out and try again with a different user. When I click this link, I expect to be redirected to the login page to try again. However, the link doesn't do anything.
It sounds like you have AutoSelfCheckAllowed enabled and the credentials in AutoSelfCheckID and AutoSelfCheckPass are for a user without self checkout permission. As I understand it, having AutoSelfCheckAllowed enabled will never let you reach the login form because it will always try to use the stored credentials. Perhaps we need some kind of message saying the problem must be resolved by an administrator?