jnicklas/carrierwave-mongoid — pull request #59 by nvdk (2012-09-18 09:12:42+00:00)
Title: Mongoid 3.0:  Issue with using multiple uploaders for a single model 

to_json returns the same url for both attachments, even though two different uploaders are used. For more information see https://github.com/jnicklas/carrierwave/issues/743 .
I've added specs that fail for mongoid.