go to nintendowifi.com and check on the right side to see if the game you want to play is working/not.
EDIT: not aimed at you directly, just as a general reference.
Join the Buy BWii Campaign and Buy BWii!
Midna is the Twilight Princess.
From what I've heard, it means that there's a temporary fault somewhere in the connection between you and the WFC - I've been getting the same error every time I try to use my local hotspot, so I guess all I can do is keep trying.