I sent an email to Witopia tech support and got a reply from them. The great firewall of China has been blocking some of their DNS servers so that none of the connections can resolve. The short term workaround is to modify the config to point to a specific ip. Witopia is working on a more permanent solution.

I suspect the problems other VPNs have reported have the same root cause.

I am using vpn choice connection www.vpnchoice.com/blog/ipad-vpn/ which was suggested by my forum friend. I really thank to him and vpn provider because of their advice now I can access banned and blocked sites in my regions.

There are number of good VPN providers around who provides Best VPN services with cheap rates. like Swiss VPN, Cryptocloud and others but i recommend you Strong VPN because it offers cheap prices and remain among the Best VPN providers. There is a lot positive about StrongVPN along with its prices. It supports PPTP, L2TP and OpenVPN, Servers are located in 19 Countries, supports almost all OS and Devices (iPhone, iPad, Android, Windows Mobile and Symbian). It offers support in English & French, in a way customer desire of, i.e. live chat, call, email and convenient remote desktop method. It also supports all reliable and mostly used payment methods, listed in the Payment Methods being supported by StrongVPN. It also offers you with comprehensive tutorials on how to set-up your StrongVPN Account and Router support.

I am using small VPN provider breakwall.net based in China with servers in HK, US, Japan and UK. So far it proved to be very reliable, customer service top notch. Very reasonable rates.