Does Cox redirect DNS?

I'm trying to set up any 3rd party DNS (OpenDNS or Google, etc.), but regardless of whether I set it on my router or my local PC it appears I'm still getting responses from Cox DNS rather than the alternative.  Going to welcome.opendns.com says I'm not using OpenDNS and any time I get a failed domain lookup, it's the Cox error page that pops up.

So is Cox intercepting and redirecting DNS?