Keyboard control sensors getting stuck as activated in game

I’m pretty new to the game engine side of blender and was working on a game to help train myself and my colleagues at work on how to fly the new DSLR Drone our company purchased. At seemingly random intervals a keyboard control will get stuck as activated even when you release the key and I can not figure out why this is happening. Here is a link to the .blend file of the game:

Controls:
W/S - Throttle
A/D - Yaw
I/K - Pitch
J/L Roll

As I am unfamiliar with python and coding in general, I used all logic blocks to make the game work. I am happy with everything except this control issue. All control actions are built into the body of the quadcopter drone. I’ve tried different methods of sending the control message from the sensor and different actuators and the problem persists. Any insight to the problem would be greatly appreciated. Thanks so much.

As there is an thread open already (see post #2) -> closed