Buffering in 3.9compact

[HeathClark]

I keep getting a error when trying to buffer geometries using the 3.9compact build.  The error is:

TypeError: h.join is not a function

in the http://js.arcgis.com/3.9compact/js/esri/tasks/BufferParameters.js file.

Sample Code:

function BufferPoint(evt) {
        var params = new esri.tasks.BufferParameters();
        params.distances = BufferDistance;
       //params.inSpatialReference = new esri.SpatialReference({ wkid: '102100' });
        params.bufferSpatialReference = new esri.SpatialReference({ wkid: '102100' });
        params.outSpatialReference = new esri.SpatialReference({ wkid: '102100' });
        params.unit = BufferUnits;
        params.unionResults = true;

        params.geometries = [evt.mapPoint];

        console.log('0' + ": feature's geometry: " + params.geometries[0].type);

        var GeoService = new esri.tasks.GeometryService('[server]/arcgis/rest/services/Utilities/Geometry/GeometryServer');
        GeoService.buffer(params, bufferResults);


    };

Where the BufferPointmethod is linked to an OnClick event.
The console log shows

0: feature's geometry: point

Any ideas?

[DasaPaddock]

params.distances should be an array of Numbers.
https://developers.arcgis.com/javascript/jsapi/bufferparameters-amd.html#distances

[HeathClark]

in short, read the documentation!  Can't believe I missed that one.