SNES Topfighter QJ Arcade Joystick Problem

[BinkyWong]

I'm trying to hook up one of these awesome SNES Topfighter QJ Arcade Joysticks:

using the SNESControllersUSB project. While it works flawlessley on my standard SNES controller, when I plug in the Topfighter QJ Arcade Joystick, all the buttons and directional inputs go haywire:

So they all flicker on/off really quickly.

Appreciate this project is not being actively worked on, but if you can give me some pointers as to what things I could potentially try or tweak in the code - I'll fork the project and if I get it working, I'll issue a pull request so compatability for this joystick could be added.