Feeder App: Press/Release input

I'm writing a simple Feeder app using .NET Forms.

I have button controls on a Form which correspond to inputs on the Virtual Joystick.  When I press the button, it should activate the corresponding input and vice versa when I release it. 

The issue I have is that the "release" method does not seem to do anything unless I put in a significant Sleep time. 

My PressButton method (called on the Clicked event) looks something like this:



       private void PressButton(string buttonName)
       {
           switch (buttonName)
           {
               case "Up":
                   _state.AxisY = 0;
                   break;

               case "Down":
                   _state.AxisY = 0x8000;
                   break;

               case "Left":
                   _state.AxisX = 0;
                   break;

               case "Right":
                   _state.AxisX = 0x8000;
                   break;

               default:
                   return;
           }

           _joystick.UpdateVJD(_id, ref _state);
       }


The ReleaseButton method (called on MouseUp for now) does something similar except it sets the corresponding Axis to neutral. As I mentioned though it doesn't do anything unless I use a Thread.Sleep() with a high enough value.

What am I doing incorrectly?


EDIT:  It seems the issue is with the app I'm testing (Mame).  It works fine in other apps.