Hello Vegas!

I picked up a problem last night when I decided to play the Lonesome Road DLC on my Steam Purchased PC game.

The Problem:

Picking up the laser detonator and whilst it fires the first time on the first warhead in which you'll have to blow up to pass, when you use it the 2nd time...it won't fire.
After that, as you switch to other guns, it'll fire one shot (as if the button is stuck) and refuses to fire again until I switch to another game, in which it'll fire just one shot.

I've searched the problem on google, and it seems to be rare but only 1 or 2 people I've read who posted similar problems have had no responses.

Please help

Thanks!