Node-Webkit with external module containing native code

I'm using node-webkit with an external module called edge.

According to the node-webkit docs modules that contain native code must be recompiled using nw-gyp as oppose to node-gyp. I was able to recompile without error and node-webkit seems to import the module OK.

Heres my code. The code I'm trying to use:

var edge = require('edge.node');

var hello = edge.func(function () {/*
async (input) => 
{ 
    return ".NET welcomes " + input.ToString(); 
}
*/});

hello('Node.js', function (error, result) {
if (error) throw error;
console.log(result);
});

Which throws the following error when run within node-webkit.

Uncaught TypeError: Object [object Object] has no method 'func' 

If write the object out to console.log I can see:

 Object {initializeClrFunc: function}
 initializeClrFunc: function () { [native code] }
 __proto__: Object

So the module seems to have loaded. If I run the same code outside of node-webkit, everything works perfectly and I can access the func function. This is driving me crazy - and any help would be really appreciated.