IE9 uses following key names which are not defined in D3E spec:
"Pause" for VK_PAUSE. This is the key at right of ScrollLock key on full keyboard.
"Play" for VK_PLAY. I'm not sure which keyboard layout has this key. I guess this was in non-PC's keyboard.
I think that Gecko will use same key names for them. Therefore, I'd like D3E spec will add them into the key name table.
I was definitely able to see "Pause" on the key next to the scroll lock. I can't seem to get my MediaPlay, MediaPause key to fire a VK. I'm also not sure where the regular "Play" key would be, but I can certainly add these into the spec;
Fixed in the latest version of the spec: r240