W3 Validation Problem

Dear sir

I want to inform you that i have some problem when i click the w3c validator
image at my site. My site has 0 validation error but when i click your image
then i found this message from your site
Sorry! This document can not be checked.*No Referer header found!

*

You have requested we check the referring page, but your browser did not
send the HTTP "Referer" header field. This can be for several reasons, but
most commonly it is because your browser does not know about this header,
has been configured not to send one, or is behind a proxy or firewall that
strips it out of the request before it reaches us.

This is *not* an error in the referring page!

Kindly resolve my error

Regards
Junaid Afzal