VPN Software Witopia--Does it bypass wifi router firewall?

I live and work in Mainland China. There are a lot of sites I'd like to visit that I'm unable to do so because they're blocked. I'm a bit paranoid about internet security, especially here. I always connect behind a strict firewall on my wifi router (D-Link DIR-655) with SPI and NAT in addition I have the firewall on Snow Leopard set the strictest---to block all incoming connections. What I'm concerned about, is the VPN software of Witopia bypassing that firewall in my router. Will this happen? Does anyone know about the fine details of Witopia's VPN software and what it's doing, how it's connecting, etc? I'd really appreciate some info in this area.