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USB port should be the one closest to the edge (Lowest USB port if the Wii is flat)
Could be a badly formatted HDD (USB Sticks have there own issues) [I might of said it was HDD read speed but...

I don't know enough about the hardware but I know Wode really is not needed today at all but will save a little extra software modding and save the need to format a HDD in a certain way though

If...

I need to double check as don't remember off the top of my head but was sure that it made no difference what firmware you are on as long as there is an exploit for it, you are better off just not...