Reloading in the console stops observer callbacks

Calling reload! in the console stops all observer callbacks from being fired on new instances of records (old records in memory still work).

class GizmoObserver < ActiveRecord::Observer
  def after_save(gizmo)
    puts "after_save(#{gizmo})"
  end
end

And now in a console:

$ rails c
Loading development environment (Rails 3.0.3)
ruby-1.9.2-p0 > (g = Gizmo.first).save
after_save(#<Gizmo:0xa59df94>)
 => true
ruby-1.9.2-p0 > reload!
Reloading...
 => true
ruby-1.9.2-p0 > Gizmo.first.save
 => true
ruby-1.9.2-p0 > g.save
after_save(#<Gizmo:0xab806b4>)
 => true