Nested RESTful Routes and creating a object from XML

I am trying to create a new model from XML that contains has a has_many
relationship. Is this possible without having to write code to parse
the XML or to doing multiple POSTS? I can do a post with XML that
doesn’t contain any of the has_many elements and it works fine. It is
when I add the items from the has_many relationship that I get a bunch
of errors.

Here are the examples I am trying

This works…

orange
This is track 3
RFI 3
Joe

This doesn’t

orange
This is track 3
RFI 3
Blow


20.0
25.0


30.0
35.0


Error from cURL about ActiveRecord::AssociationTypeMismatch in Manual
tracksController#create

this fails too…

orange
This is track 3
RFI 3
Blow

20.0
25.0


30.0
35.0

NoMethodError in Manual tracksController#create
undefined method `position=’ for #<ManualTrack:0x47ec8dc>

Any suggestions of what I need to do?
Thanks!
CW