I had the same problem after about 5 mths of no problem operation; eliminating 'Channel Auto Scan' and locking Router on Channel one fixed this problem for me [even though more often than not, I have to wait for my w'less connection to be reestablished if my computer has been in sleep mode overnight]
However, I've been having problems with this router dropping my Wii connection after playing 1/2 to 2 games. Wii CONNECTION ERROR 91010:
Here's what fixed my erratic CONNECTION ERROR.
*In the router's menu:
Under ADVANCED SETTINGS/FIREWALL SETTINGS/ NAT ENDPOINT FILTERING
for UDP & TDP ENDPOINT FILTERING; select the first option:
'ENDPOINT INDEPENDENT'.
That's it.. I've had no connection problems with the Wii since...
.. Maybe that could solve your problems as well?
Good Luck