Problem Impossible to modify keys assignation

Hello !

I'm trying to set up a USB numpad to use it as a button box. But I have a problem : "+" and "-" keys don't want to be assigned to what i want. I have assigned new functions on these keys in the menut and everything seems to be OK, there is no apparent conflict. When I press on it, it changes the camera : it sends me inside the other cars, forward when i push on "+", backward when i push on "-".

What can i do to change that, please ?

Thank you !

 

The same problem here.
Any solutions?

Thanks!

 

I think these keys are hardcoded and can't be assigned to something else.

 

Okay, it's too bad...