I have a chained polymorphic relationship. I will try to describe it as best as I can. Imagine: Group (polymorphic) \ | Tag (polymorphic) \ | Article The idea being I can TAG many ARTICLES. I can also GROUP many TAGS. And enjoy using both TAG and GROUP in more creative ways. I also use proxy classes (GROUPABILITY and TAGABILITY) to encapsulate the relationships. Both Groupability and Tagability are where the :polymorphic => true statement resides. Then I use has_many with a :through statement to do most of the relational work. Group \ > Groupability (real polymorphic) | Tag \ > Tagability (real polymorphic) | Article After creating this relationship, the Tagabilty works just fine. The Tagable_id and Tagable_type field are populated correctly. The Groupability appears to work fine HOWEVER while the groupable_id field is populated correctly , the groupable_type field remains nil. I (believe) I have checked all my syntax which looks correct. Are there any known bugs with this type of chained polymorphism or some trick I am missing? Is the belongs_to <NAME> on the polymorphic true line, simply appended with "_type" to determine the proper field in the database to set the value? Is there a manual way of setting the <NAME>_type field for the proper class? How can I debug this when I am getting no errors? Steve Woolley swoolley-T/z87HSYmD2Wd6l5hS35sQ@public.gmane.org