Extract from an email i received from 12vpn team
2011/06/28 - China DNS poisoning
During the National People’s Congress in March this year China blocked the IP addresses of 12vpn.com as well as some of our competitors, including strongvpn.com and witopia.net. We responded to this by changing the IP addresses of our website and our servers. China then blocked these new IP addresses and we changed them again. This cycle repeated a few times until the National People’s Congress was over. Most of our users never noticed this as it's something we can do very quickly.
For the upcoming 90-year anniversary of the Communist Party of China (CPC) China has chosen a different approach: DNS-poisoning. This means that any VPN server or website that ends with “12vpn.com” will be unreachable from China. The only way to solve this is by changing our domain name. This is more troublesome than the IP blocks because it's time consuming on our end and each time we change our domain name affected users will have to re-download and re-install our software. It's likely that, at least until the anniversary celebrations are over, new domains will be blocked quite quickly.
A characteristic of DNS poisoning is that it takes some time to take effect. Some users in China are already affected, while other may not notice it until days or even weeks later. We consider it unlikely that China will undo the poisoning after the CPC’s anniversary so eventually all our China based clients should be affected.
If you’re affected, first try other servers. Due to how the poisoning works you may get "lucky". Once connected, try to stay connected until after the anniversery. If you really can't connect, please reply to this e-mail with your username and windows/mac version and we’ll do our utmost to help you through the anniversary period. Due to the special circumstances, our replies may be a little slower than usual. We thank you for your patience.