Right, I don't know if any of these will help ?
http://www.d-link.co.uk/?go=jN7uAYLx...LhJk8Vtejcboey
But other then turning on the encryption, and loading the host machine with as many firewall's as your system can handle, there's not much else you can do. I can connect to my next door neighbour's wireless setup, and he can connect to mine if he wanted to.