Upgrade from Mongoid 3.0.23 to 3.1.2 causes test failure - need to reload other side of the relationship to get test to pass

gistfile1.txt

[1] pry(#<Activity>)> activity
=> #<Activity _id: 512e3ef99a4b7cecef000005, created_at: 2013-02-27 17:14:33 UTC, updated_at: 2013-02-27 17:14:33 UTC, slug: {"en"=>"activity2", "id"=>"activity2"}, search_slug: {"en"=>""}, category_ids: ["512e3ef99a4b7cecef000006"], name: {"en"=>"activity2"}, position: nil, icon: nil>
[2] pry(#<Activity>)> activity.categories
=> [#<Category _id: 512e3ef99a4b7cecef000006, created_at: 2013-02-27 17:14:33 UTC, updated_at: 2013-02-27 17:14:33 UTC, slug: {"en"=>"category3", "id"=>"category3"}, search_slug: {"en"=>"category3", "id"=>"category3"}, parent_id: nil, activity_ids: ["512e3ef99a4b7cecef000005"], level: 0, name: {"en"=>"category3"}, description: nil, group: nil, classification: "Category", position: 1>]
[3] pry(#<Activity>)> category1
=> #<Category _id: 512e3ef99a4b7cecef000006, created_at: 2013-02-27 17:14:33 UTC, updated_at: 2013-02-27 17:14:33 UTC, slug: {"en"=>"category3", "id"=>"category3"}, search_slug: {"en"=>"category3", "id"=>"category3"}, parent_id: nil, activity_ids: ["512e3ef99a4b7cecef000005"], level: 0, name: {"en"=>"category3"}, description: nil, group: nil, classification: "Category", position: 1>
[4] pry(#<Activity>)> category1.activities
=> []
[5] pry(#<Activity>)> activity.metadata
=> nil
[6] pry(#<Activity>)> category1.metadata
=> {:relation=>Mongoid::Relations::Referenced::ManyToMany,
 :extend=>nil,
 :inverse_class_name=>"Activity",
 :name=>:categories,
 :class_name=>"Category",
 :inverse_of=>:activities,
 :validate=>false}
[7] pry(#<Activity>)> category1.reload
=> #<Category _id: 512e3ef99a4b7cecef000006, created_at: 2013-02-27 17:14:33 UTC, updated_at: 2013-02-27 17:14:33 UTC, slug: {"en"=>"category3", "id"=>"category3"}, search_slug: {"en"=>"category3", "id"=>"category3"}, parent_id: nil, activity_ids: ["512e3ef99a4b7cecef000005"], level: 0, name: {"en"=>"category3"}, description: nil, group: nil, classification: "Category", position: 1>
[8] pry(#<Activity>)> category1.activities
=> [#<Activity _id: 512e3ef99a4b7cecef000005, created_at: 2013-02-27 17:14:33 UTC, updated_at: 2013-02-27 17:14:33 UTC, slug: {"en"=>"activity2", "id"=>"activity2"}, search_slug: {"en"=>""}, category_ids: ["512e3ef99a4b7cecef000006"], name: {"en"=>"activity2"}, position: nil, icon: nil>]
[9] pry(#<Activity>)> activity.metadta
NoMethodError: undefined method `metadta' for #<Activity:0x007fe8dfa4d920>
from /Users/dbk/.rbenv/versions/1.9.3-p392/lib/ruby/gems/1.9.1/gems/mongoid-3.1.2/lib/mongoid/attributes.rb:318:in `method_missing'
[10] pry(#<Activity>)> activity.metadata
=> nil
[11] pry(#<Activity>)> exit
     FAIL (3:00:23.654) test_0003_can have categories assigned
          --- expected
          +++ actual
          @@ -1 +1 @@
          -[#<Activity _id: 512e3ef99a4b7cecef000005, created_at: 2013-02-27 17:14:33 UTC, updated_at: 2013-02-27 17:14:33 UTC, slug: {"en"=>"activity2", "id"=>"activity2"}, search_slug: {"en"=>""}, category_ids: ["512e3ef99a4b7cecef000006", "512e3fc49a4b7cecef000007"], name: {"en"=>"activity2"}, position: nil, icon: nil>]
          +[]