When trying to create a new event template from scratch, when you get to the online registration section and attempt to enable it, it doesn't change that for an existing Event template, but instead creates a new blank template. Reproduced on CiviCRM 4.1 / Drupal 6 demo site.
Steps to reproduce:
- Events -> Event Templates -> Add Event Template
- Fill out template hit save
- Click on Online Registration Tab
- Enable Online Registration and save
You will be thrown to events, not event templates. If you navigate to event templates you'll see that your event template was not saved, but a new event template with no name was created.