event registration page does is not reset properly when the user is logged-in

The registration page for CiviCRM is populated with the last individual that registered, when the user is logged into Drupal, and changes to the name update the previous record rather than creating a new contact.

To recreate this on the demo
1. Ensure you are logged in to the demo.
2. Click on the event registration link for an existing event (e.g. 'Progressive Supper' currently in the demo)
3. The fields on the registration page are populated with the previous individual (John Doe) that signed up. Make changes to the email and name (Mike Smith) and click 'Continue' until the registration is complete.

Go back to the CiviEvent page click the link to see the list of participants in the event. Mike Smith now appears twice, and John Doe does not appear. This is because edits to the name and email fields were updates to John Doe's record, and then that same individual was registered a second time in the event. Note that this behaviour does not happen if the user goes to the event registration link with logged out of Drupal.

I would assume that correct behaviour for the event registration is the it is initially empty, and if the entered email does not match data in the data base then a new record is created.