Num1 or NumEnter won't work as incoming

Hi,
the weirdest thing is happening I can't use Num1 or NumEnter as an incoming keystroke, it won't trigger my outgoing information. the rest of the keys on the numeric keypad work. Is this a bug, or am I doing something wrong?

On a Mac, 10.10.5
Bome 1.8.1 (had this problem on previous version as well)

Hi, we have to check this out. In principle, it should work, though it might be a bug...
Florian

thanks for looking into it!