When I check the shopping cart option Confirmation Page -> Configuration Require Login, existing users are unable to login during checkout. A message is displayed “User name exists, please select a different user name.

It appears that the Require Login option us usable for creating new accounts, not for logging-in on pre-existing accounts. This is confusing to the user. Since this is a prompt for login it should allow existing users to logon to the site.

Thanks, I tried using the “Show Login Screen” under General Cart Configuration as described in your post. I can see the “Sign In to Your Account” box. When I try to login using an existing DNN account, it doesn’t work. The same account works fine when I use the native DNN login.