Distance - Color RGBLED + Distance sensor HC-SR04 (having strange results)

further to this, now I have set it up to only trigger on button 1 press, each time it is pressed it returns several times:

Code:

var sensor = require("HC-SR04").connect(A2,A3,function(dist) {
  console.log("response "+Math.floor(dist)+" cm away");
});

function runIt(){
  console.log("button pressed");
  sensor.trigger();
}

runIt();

setWatch(runIt, BTN1, {repeat:true, edge:"rising"});

Results:

button pressed
response 27015 cm away
response 11 cm away
response 13 cm away
response 109 cm away

I would expect one response per trigger, or am I missing something?