undefined method "set_model_target"

[tokland]

Rails: 3.1.0
preferential commit: eed83c2

lib/has_numerous.rb. line 67: "pref.set_model_target(self)"

u.preferences_color = "red"
NoMethodError: undefined method `set_model_target' for #Preference:0x7ff84a06bd38

My workaround: "pref.model = self"