TypeError: can't convert RSpec::Mocks::Mock to Hash

controller

def create
@money_order = current_user.money_orders.build(params[:money_order])
if @money_order.save
@money_orders = current_user.money_orders.staged
flash.now[:msg_ok] = “Added money order for:
#{number_to_currency(@money_order.amount)}”
end
respond_with(@money_order)
end

#controller spec
describe “POST create” do
describe “with valid params” do
it “assigns a newly created money_order as @money_order” do
MoneyOrder.stub(:new).with({‘these’ => ‘params’}) {
mock_money_order(:save => true) }
post :create, :money_order => {‘these’ => ‘params’}
assigns(:money_order).should be(mock_money_order)
end
end
end

#returns this error
Failure/Error: post :create, :money_order => {‘these’ => ‘params’}
TypeError: can’t convert RSpec::Mocks::Mock to Hash
(RSpec::Mocks::Mock#to_hash gives RSpec::Mocks::Mock)

#gems
rails (3.0.4)
rspec (2.5.0)
rspec-core (2.5.1)
rspec-expectations (2.5.0)
rspec-mocks (2.5.0)
rspec-rails (2.5.0)
… and a few others

Must be missing something simple, but I just don’t see it. What is
causing the error?