Billing is set as a primary When participant is registered for a event

• Created a profile with fields

• First Name(Individual)
• Last Name (Individual)
• Street Address (Home)(Contact)
• City (Home)(Contact)
• Postal Code (Home)(Contact)
• Country (Home)(Contact)
• State (Home) (Contact)

And added the profile in an non paid Event.
(note : Home is my default address in location type. )
Now when and anonymous user register for this event, his contact id is created and his all information is address saved in home address(coz we have fields of home address). But if you view that contact id, his email which he has provided while registering the event goes in Billing address and his billing address becomes his primary location.
Due to which if you want to export the name and address fields of the participants(primary fields) of that event, the address fields are blank in csv, because currently our billing address is our primary address and our data is stored in home address.

The issue is replicated on demo site with event : http://drupal.demo.civicrm.org/civicrm/event/register?id=12&reset=1

Attached the screen shot of contact id profile after he registers for event.