I was having all sorts of problems trying to get my Wii online. It kept saying it couldnt connect to the internet etc etc.
I am using a Speedtouch 585 which connects to the internet on my Non Wifi pc via a belkin USB dongle (£20 from PC World).
in the end all i had to do was change the settings on my Wii (Just the ip address) and it worked!!
say the address was 10.130.120.20 i changed it to 10.130.120.30 (I.E added 10 to the last part to ensure there was no conflict) and days worth of tring static IP etc etc done with!!
So just thought id post as i was changing the IP but not like that and it wasnt working. i tried changing it by a couple of numbers etc so hopefully this will help someone