I added my master-detail relationships in the wrong order and need to change my object's primary relationhip. From [the docs](http://na14.salesforce.com/help/doc/en/relationships_manytomany.htm):

> 
> The first master-detail relationship you create on your junction
>  object becomes the primary relationship.
> 
> 
> 

I tried deleting (and erasing) both relationships but when I re-add them the incorrect object is still showing as the primary relationship. Is there a way to change the order without deleting the entire object?