Assuming you mean Virgin Media UK. How did you determine this?
We cross-checked the reports of dozens of our customers with Virgin Media UK, asking them to resolve "airvpn.org" on two of Virgin DNS servers. Since all the reports matched exactly throughout one year, we can safely assume that the reports are reliable. It is also worth mentioning that DNS poisoning of airvpn.org is intermittent, and when contacted directly about the issue, Virgin Media responded to us that it was a technical problem, totally unintentional.
Why would they mess with DNS to the web site rather than routing to the actual OpenVPN servers?
How are we supposed to know? All in all even the cyber workers of the government of China are interested in our web site, not only with DNS poisoning but also IP blocking. Who knows, maybe it's really just an obscure technical error that re-occurs periodically.