ActiveRecord fails to handle to_many relations sanely during MyArModel.new()

Rails can create XML such as this:

<my-ar-model>
    <foo type='float'>124.0</foo>
    <bar type='float'>0.0</bar>
    <created-at type='datetime'>2010-10-04T10:50:59Z</created-at>
    <id type='integer'>23</id>
    <updated-at type='datetime'>2010-10-04T10:50:59Z</updated-at>
    <images type='array'>
        <image>
            <id type='integer'>15</id>
        </image>
        <image>
            <id type='integer'>16</id>
        </image>
        <image>
            <id type='integer'>17</id>
        </image>
    </images>
</my-ar-model>

Feed it back into Rails, and it'll create a hash like:

{"my-ar-model"=>{"foo"=>124.0, "bar"=>0.0, "images"=>[{"id"=>15},{"id"=>16},{"id"=>17}], ...}

Yes, there are bits left out. The hash for the images to_many relation is at issue. When using this hash to create a new AR record, this dies with the following (partial) backtrace:

ActiveRecord::AssociationTypeMismatch (Image(#70247453816860) expected, got HashWithIndifferentAccess(#70247494361020)):
    /vendor/rails/activerecord/lib/active_record/associations/association_proxy.rb:256:in `raise_on_type_mismatch'
    /vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:310:in `replace'
    /vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:310:in `each'
    /vendor/rails/activerecord/lib/active_record/associations/association_collection.rb:310:in `replace'
    /vendor/rails/activerecord/lib/active_record/associations.rb:1322:in `images='
    /vendor/rails/activerecord/lib/active_record/base.rb:2589:in `send'
    /vendor/rails/activerecord/lib/active_record/base.rb:2589:in `attributes='
    /vendor/rails/activerecord/lib/active_record/base.rb:2585:in `each'

The expected behavior is for Rails look up the Images by ID and add them to MyArModel's : images to_many relationship.

Environment:
Ubuntu 9.10 (using Ubuntu's ruby1.8 and rails packages)
Ruby 1.8
Rails 2.2.3