Arduino and the web

Hi, I am trying to use arduino and the ethernet shield to connect to the web. However, if I try to make a request, it works in the first time , but then for the next attempt, it won't work. I guess I am getting blocked or my access is denied. I am using mac Dns connection instead of ip . Any ideas?

this is the message i get

HTTP/1.0 302 Moved Temporarily Server: squid/3.0.STABLE13 Mime-Version: 1.0 Date: Thu, 26 Apr 2012 14:51:06 GMT Content-Type: text/html Content-Length: 0 Expires: Thu, 26 Apr 2012 14:51:06 GMT Location: X-Squid-Error: 403 Access Denied X-Cache: MISS from squid X-Cache-Lookup: NONE from squid:3128 Via: 1.0 squid (squid/3.0.STABLE13) Proxy-Connection: close

That appears to be a router attempting to redirect your request to the local proxy server (squid). It will cache the page, and if you request it again within a specific time period, it will send you to the cached page on the proxy server.