domain_current_site on multisite when doing domain mapping

Strange - have a few of these up and running but this one seems to be the bugger.

While doing a domain mapping - when I go to a domain mapped It redirects to opendns

http://www.website-unavailable.com/main?wc=EWJpHhd5BRhfARFuAA%3D%3D&url=domain_current_site&w=1635&h=646&ifc=0

some odd reason the system is trying to go to domain_current_site