Iam parsing a page and im getting response from that but after some time i.e. after some of the parsing gets done i get this error from the server -

Proxy Error

The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request GET /file.php.

Reason: Error reading from remote server

and after this my parsing fails. I even tried sleep() function but it didnt helped and the error still came.

Are they temporarily blocking my ip or what?? What could be the reason for this and how can i parse those pages without getting this error and all ???