Well it should work as thats what I had to do when it wouldnt work It only finds stuff in the root directory and if you have say a folder
called ROW79 and extract into that you have to open it and copy the shown folders and the file onto the card.
I didnt the first time and it couldnt find anything so I went back to the ROW76 card I had and looked at how it was.
I did it like i posted and it worked. I actually just copied it onto a card with stuff on it and it found the folders Ok and installed the update.
If you use Discover care it formats the card first