Aaf - I can't add new fields search


I’m workin with acts_as_ferret plugin y the is indexed like this:

acts_as_ferret :fields => [:name , :description]

but, now i need add a new field to search and make my model like this:

acts_as_ferret :fields => [:name, :description , :lastname]

but when i put this, doesn’t work.

I is still looking in :name and :description fields.

I don’t know why this happen, I hope you can help me.

Sorry by my bad english, bye and thanks!!