Those dns tests fail for me when I try to run them behind the firewall at work. I haven't looked into the details of what might be blocked -- I am able to do ordinary DNS lookups through outside nameservers using, for example, nslookup, but these tests do something that the firewall blocks.
On the other hand the failure looked the same when I broke Net::DNS when I was working at on it, so I am not saying that there is no bug in your case, only that you should check for a firewall problem. -- sidney
