PhantomXHR | Ajax mocking in PhantomJS | Unit Testing library

I am using PhantomXHR along with CasperJS to implement frontend functional testing along with stubbed out AJAX requests.

The faked XHR requests and stubbed responses work great in a page that is already initialized and the AJAX request is triggered by a user action such as a click or a keyup.

When trying to initialize a faked XHR request upon page load, however, I cannot get it to work. Is this a bug, or what is the recommended way of going about this?

I am using Marionette and Backbone in my SPA and upon initialization of a template, if certain conditions are met, an AJAX call is made. I cannot get PhantomXHR to fake this request no matter what I do.

I have tried initializing PhantomXHR and the faked request before calling casper.start('http://localhost:3000/my/foo/bar'), I have tried calling casper.start(), initializing the PhantomXHR and then doing casper.open('http://localhost:3000/my/foo/bar'), nothing seems to work. Can anyone tell me the proper way to do this?