ActiveResource: a tag that has the same name as an existing class

I've got an ActiveRecord::Base class named Tracker. I've also got an
ActiveResource class named MyConfig that will read an xml file that
looks like:

<my-config>
  <tracker>
    <name>foo</name>
  </tracker>
</my-config>

class MyConfig < ActiveResource::Base
  self.site = "http://localhost"
end

If I do MyConfig.find(1), I get:

NoMethodError: undefined method `name=' for #<Tracker:0x2487378>

ARes apparently creates new classes for all these sub-elements, and it
does them in the MyConfig context (so it should make
MyConfig::Tracker). If I type MyConfig::Tracker into the console, I
get

MyConfig::Tracker

(irb):13: warning: toplevel constant Tracker referenced by MyConfig::Tracker
=> Tracker

Why is it doing this? And how do I fix it? I need to keep my Tracker
ActiveRecord class, and the xml file has to have the <tracker>
element.

Pat