Probably just a caching issue. On one of the servers in question, try doing 'ipconfig /flushdns'. Then go try the site again. Actually it depends on your DNS structure. If you have a heirarchy, where they reference each other, then go to your top-most DNS server.
You could also use the 'nslookup' command to query your DNS server to see what IP it gives you for scenaradvantage.com.au.