Model namespace trouble

Hi,

I have trouble trying to put a model in a namespace...

For example, I have a "normal" model (outside of my namespace) named "Foo" and a namespace named "Bar", which have only one model named "Baz".

app/models/foo.rb

class Foo < ActiveRecord::Base
end

app/models/bar/baz.rb

module Bar
  class Baz < ActiveRecord::Base
  end
end

>> Bar::Baz
=> Bar::Baz # return the right model

>> Bar::Quux
=> NameError: uninitialized constant Bar::Quux # raise an error as expected

Everything is normal until here... but when I try to call an model which don't exist into my namespace, but exists outside of the namespace, it returns a model the first time, and an error the following times...

>> Bar::Foo
=> Foo # return a model instead of raise an error
>> Bar::Foo # call again
=> NameError: uninitialized constant Bar::Foo # return an error, which normaly have to be raised the first time...

Is there anybody who can help me please ?