I'm using BlogEngine.NET 2.0 and when logged in as an admin, then go to Settings > Comments
When I unselected "Enable comments" or "Moderate comments", I got the following error:
A Runtime Error has occured.
Do you wish to Debug?
Error: Object expected
Also I've noticed that enabling the Moderate Comments option does not work in this version. Even though this option is selected, anyone is able to post a comment without approval.