RSS Validator and "Server returned HTTP Error 302" Error

i have a php file in my site that create my rss, and i can see result by browser. but when i want to check by http://ift.tt/1FWZF76, i got this error:

Server returned HTTP Error 302: The HTTP server returned a redirect error that would lead to an infinite loop

and when i want to get rss by file_get_contents, i got this error:

failed to open stream: Redirection limit reached, ...

please help to solve this problem. thanks everybody ;)