Right and Middle mouse buttons not working on one machine.

HI,
I'm having a bit of trouble with one of my clients machines. It seems to not be detecting right and middle mouse clicks. This works on most machines so I'm a bit stumped. We have tried multiple mice.
Currently I'm using:

Code (CSharp):

1. if (Input.GetKeyDown(KeyCode.Mouse1))

would I be better using:

Code (CSharp):

1. if (Input.GetMouseButtonDown(1))

or are they the exact same code underneath?

 

So a working mouse works on one system, but the same mouse doesn't work on another? And "seems", have you confirmed via debugging?

 

Some mouse drivers allow remapping of mouse buttons. This may have been done on this machine.