i'd first suggest editting your message and removing your email address.
you *might* get spammed otherwise.
ok, what linksys router are you using?
i've had issues with a linksys WRT54GS and the Wii, which to a degree
i have now "solved". the downside is that although i can use the internet
channel (via opera) i can't access the weather channel....the update feature
worked ok though.
this is what i did.....
1. turned off (LAN) DHCP on the 54GS
2. enabled WPA-TKIP encryption
3. entered the Wii's MAC address into the permitted MAC access list.
4. set wireless speed to 802.11g only
5. rebooted the router.
6. created a "new" wireless connection in the Wii's internet settings.
7. entered all relevant IP / default router (gateway) information manually.
8. ...and probably most crucially, under DNS settings, i entered my actual ISP
primary and secondary DNS addresses, rather than using the routers IP
as the DNS value
if you feel confident making these changes, have a go.
post back if you experience any more issues.