Movie Maker Won't let me upload footage!

i download clips from Veoh, and when i try to upload the clips now the Movie Moaker says “C:\Documents and Settings\Anthony\My Documents\My Videos\Veoh\ShugoChara43chibi.avi could not be imported. The required codec was not downloaded automatically because the Download codecs automatically check box is not selected in the Options dialog box."
Whats wrong, and how do i fix it? i downloaded this codec “ff” something or other, but it still won’t work!

Can you feed said AVI into gspot and report what it says?
instructions: http://www.moviecodec.com/topics/61931p1.html