CurrentSiteManager needs models.Manager() for admin to function.

Not only do you need to define the models.Manager but you must use the same order as in the example or even that won't work.

For example, this works:

class Rabbit(models.Model):
    title = models.CharField(maxlength=50,core=True,blank=False)
    site = models.ForeignKey(Site,core=True)
    objects = models.Manager()
    on_site = CurrentSiteManager()

This doesn't:

class Rabbit(models.Model):
    title = models.CharField(maxlength=50,core=True,blank=False)
    site = models.ForeignKey(Site,core=True)
    on_site = CurrentSiteManager()
    objects = models.Manager()

This isn't an error, but the docs could do a better job of pointing at the documentation for custom managers, which does explain that the first manager defined for a model will be the default one, and that defining one or more custom managers will cause the "automatic" objects manager not to be created for you, so that you'll have to create it manually if you want to keep it.

(In [3686]) Fixed #2609 -- Improved docs/sites.txt CurrentSiteManager? to explain gotcha with models.Manager

Actually, the documentation is somewhat wrong ...

The administration doesn't use the appropriate object all of the time ... check out line 216 of db/models/options.py

self.manager = manager or Manager()

This manager gets used in a number of places, more importantly it gets used by the ChangeList? class for the admin interface, so the change list shows instances of the model for all sites, regardless of whether your CurrentSiteManager? is first or not ...

I hope you don't mind that I'm re-opening the ticket. At the very least, the documentation should be updated.

Sorry, my comments are a duplicate of #2892 #2644. Changing back to fixed ...