Make sure you wep wireless authentication key is the fist key. I made that mistake with my 360. I set the encryption key to slot 3 and it could only look for it on key 1
WBuck wrote: Have you enabled the Wireless MAC Authentication in Advanced Security Settings? If so, you will need to add the Wii to access list. No other suggestions come to mind. Good luck.
You would only need to do that if you enabled the wireless to do that. by default it is turned off.
Login to the router.
Change the router channel from automatic to channel 1 or 11.
Save settings.
Check all other devices which connect to the router wirelessly (ie. laptop, PDA, etc)
This worked for me and all my devices continued to connect.