testkeys gives mostly the same result as key binding options dialog.
Except, it returns enter instead of pad-enter, 0, 1, 3, 9 and . instead of pad-key
Curiously, it returns ENTER, but with shift it is shift-pad-enter.
Your keyboard surely could be the problem.
Have you tried windows On-Screen Keyboard? It has an option to display a numpad as well.
For me, the keyboard and OSK seem to behave the same.
event2name() I guess isn't as good as whatever is done in key bindings.