System.exactDomain Help

I need to access a PHP file which is in the sub-domain.

www.subdomain.mysite.com

My swf file is in the main domain

www.mysite.com

I am using SendAndLoad method, but i understand that with Flash 2004 it needs to be in the exact domain for it to work.

I searched some articles, which suggested me to use

System.exactDomain=false; on the first frame of the movie.

But it is not working. Any otherways you suggest?