Unable to add product to a custom collection
===

Using the shopify gem I'm trying to add a product to a custom collection.

    c = ShopifyAPI::CustomCollection.first(:title => "Man")
    p = ShopifyAPI::Product.find(95448374)

If I try:

    c.products << p
    c.save
    => true

But the product is not added to the custom collection.

I also tried 

    p.collections << c
    p.save
    => true

But still the product is not added to the collection...why?

Any help is greatly appreciated!

Augusto
