WeakRef::RefError: Invalid Reference - probably recycled

[ponny]

I get this error in both development and production when trying to use "Mass.print":

"WeakRef::RefError: Invalid Reference - probably recycled"

gems/ruby-mass-0.1.3/lib/mass.rb:36:in block in index
    from gems/ruby-mass-0.1.3/lib/mass.rb:35:in each
    from gems/ruby-mass-0.1.3/lib/mass.rb:35:in inject
    from gems/ruby-mass-0.1.3/lib/mass.rb:35:in index
    from gems/ruby-mass-0.1.3/lib/mass.rb:44:in count
    from gems/ruby-mass-0.1.3/lib/mass.rb:53:in print