Is the adapter marketed as working with the wii?
I did a quick search and I found this page that explains that all adapters do not work. I don't recognize any of the company names on the "does" work list except for the WII branded one.
Just so we are on the same page.
You are connecting the usb into wii and running an ethernet cable from the usb adapter to one of the LAN ports on the Actiontec router not the WAN port thats on the top.
Well then I've got nothing else.
Most of the hits on google when searching for the Error Code pointed to it not getting an IP address. One work around is to give the wii a static IP.