In IE, go to Tools>Internet Options>Connections>Lan settings... and uncheck all the boxes. Hit ok, and restart Internet Explorer.
Wildblue wants you to connect through their proxy, but it is unnecessary. When you use their proxy, it looks like your IP address is constantly changing. Since you logged in with one IP address and it changes when you make a post, the board wants to make sure that you're still who you say you are.