I tried tracking it down initially, but got rather lost. @instance is defined in one place, which leads me to believe Evaluator#instance= isn't getting called, but I am not sure why. I am not sure if this has anyting to do with it or not, but I have the following line in a number of my factories:

initialize_with { new attributes }

I am fairly certain I am using FactoryGirl well outside of the 90% use case. Unfortunately, this is happening in a private repo or I would point you to it. I may see if I can create a sample app, but I doubt I'll have time for it until at least this weekend.