If you want to use an alternative DNS to IDNet's, the simple solution is to use OpenDNS (http://www.opendns.com/). For most people, the switch is as easy as entering the OpenDNS servers into their router, 208.67.222.222 and 208.67.220.220.
If you're having problems with a site, or web access generally, making this switch is always a useful diagnostic.