Partial Content Filtering

Hi,

We have configured our company main router to act as the DNS server and the default gateway for our LAN to forward all request to OpenDNS. We've also block all other request on port 53 by the firewall. (It's OpenWRT)

Visiting: https://welcome.opendns.com/   tell me it's all working fine.

Visiting http://www.internetbadguys.com/   give me the phising warning as excepted.

dnsleaktest.com gives me only opendns responses

Well, but what is strange is if I put a simple domain and the black list "poker.com" it is not blocked at all.
Lot of web-site like porn, gambling, video-sharing are also not blocked.
I don't understung why ? Could it be related to my ISP or some proxy ?

Please advice, Thanks,