OK, I tried CLEAR to get rid of the Shift Function.
It doesn't make any difference.
Something else I've just noticed though is that on an initial Press On it gives a code 18, but if you keep on holding it down after about 1 sec it changes to a code 17, which is what you get on a Key Off.
I first noticed this when trying to configure a 6 button keypad in Kega Fusion, you go through all the key presses to configure a controller, but because that particular Button effectively gives two different codes when you press it you end up with that one Button doing two functions which mucks everything up.
And this only happens if you are trying to use R Alt