I have a bizzarre case of scope chaining...

I have 2 scopes on model

:

scope :xxx, any_of({ :aaa.gt => 0 }, { :bbb.gt => 0 })
scope :yyy, -> { any_of({:ccc => nil}, {:ccc.gt => Time.now}) } # notice the evaluation time

1. When I do 

MyModel.xxx

, I get this correct criteria:

=> #<Mongoid::Criteria
selector: {"$or"=>[{:aaa=>{"$gt"=>0.0}}, {:bbb=>{"$gt"=>0.0}}]},
options: {},
class: MyModel,
embedded: false>

2. When I do 

MyModel.yyy

, I get another correct criteria:

=> #<Mongoid::Criteria
selector: {"$or"=>[{:ccc=>nil}, {:ccc=>{"$gt"=>2012-07-05 01:58:54 UTC}}]},
options: {},
class: MyModel,
embedded: false>

3. However, strange things start to happen when I chain them together.

MyModel.xxx.yyy

 results in 

{"$or"=>[{:aaa=>{"$gt"=>0.0}}, {:bbb=>{"$gt"=>0.0}}, {:ccc=>nil}, {:ccc=>{"$gt"=>2012-07-05 02:21:53 UTC}}]}

 - ie, instead of doing an 

AND(OR,OR)

, I get an 

OR

 of everything.

Wait, but there is more...

MyModel.yyy.xxx

 results in

{"$or"=>[{:aaa=>{"$gt"=>0.0}}, {:bbb=>{"$gt"=>0.0}}]}

 - wherein the 

yyy

 scope gets ignored altogether

Am I missing something or the chaining of 

any_of{{`}} is broken?