Myself and friends have noticed both with FireFox and Chrome - when you highlight most ribbons it then also draws a little box around the corresponding Medal associated with that ribbon - but it does not do this for the bottom two rows of ribbons.
The same is true for when hovering over a medal and it showing which ribbon is associated - the bottom couple rows of the medals don't then highlight a corresponding ribbon.
Love the extension!!
For some things a correspondig medal/award doesn't exist.