right... i DID have this error and i got it fixed by using a handy tutorial.
SO... to fix it for YOU, you have 3.3v2 !!!
so go here -->
[Only Registered Users Can See Links. Click Here To Register]
Then Click On The WiiHacks Picture
there i have included all the neccessary files and possibly more.
start by opening the "3.3v2 Downgrade Instructions.txt"
and follow those instructions.
then you will be able to install WADS and more!
(THERE ARE NO VIRUSES SO DONT WORRY!)
it will work, if it doesnt you didnt follow the instructions properly.
and BTW thats my little site, sorry for advertising it BUT its kinda good because it hasa few rare files that you WILL need and are very hard to find.
ENJOY.
And YES Before You Ask I Am Still On 3.3Ev2 but with it unlocked so ALL WADS etc... work (i installed cIOS aswell

)
if it works tell me, because i get bugged by these sorts of things. Lol.