Another thing you might check is if the number you are to press is found on the top of the keyboard or on the number pad. Most shift+numpad combinations are for views, but I suppose an add-on developer could assign them differently.
I am the wisest man in the world, for I know that I know nothing. - Socrates
In this case it's the numbers on the keyboard, not the Num Pad keys. The Shift + 2, 3, 4 etc. key commands open the pop-up windows on the panel. These do the same as the clickable buttons on the default panels. Just the same in all versions of FS.