Custom content types listed twice

We have a site collection where two of our custom content types show up twice and when we try to edit some properties of this content type we get an error message (Error=No two choices should have the same ID)

I don't know how this happened.  My only guess is that this site collection was imported from a backup and I think the administrator imported it once but gave it the wrong name so she imported it again. 

Is there any way to delete just ONE of these duplicated content types?  I haven't tried going to one of these content types and clicking Delete because of the two instances have the exact same ID then if I click Delete on one, I have a feeling it will delete both instance.  I know for sure  the ID of both instances is the same because first of all I got that message above and also when I go to edit the content type the URL shows the ID and both instances of this content type show the exact same ID in the URL.

thanks,