I'm having trouble deleting the records in an embeds_many collection on MongoHQ via MongoID.

Decks embeds_many Cards

When I call
@deck.cards = []
or
@deck.cards.delete_all

I get: Cannot apply $push/$pushAll modifier to non-array

Alternatively, if I delete the records individually, the cards collection gets replaced with a hash instead of an Array.

Code is at
http://github.com/DanielHeath/Cards/blob/delete/app/models/deck.rb

Line 19 can be replaced with self.cards = [] or self.cards.delete_all