Wordpress multisite and ajax

Hi everyone,

I am delving into using multisite in Wordpress. I have a main site which is just a language selection screen.

I have then have a /us/ for USA users and a /uk/ for British users.

All is working fine except for loading posts via an ajax request in the /us/ site.

I have followed this tutorial. http://wp.tutsplus.com/tutorials/getting-loopy-ajax-powered-loops-with-jquery-and-wordpress/

The problem I am having is when the page scrolls and makes the ajax request, it is looking for the ajaxLoop.js file in the theme which is installed in the /us/ and the root site. As the file soes not exist in the root site, I naturally get a 404.

Any ideas on why my /us/ theme when making an ajax request would try to call it from the root site?

Thaks for any help,