Strange behaviour around fs.statSync

running this prints "..." on screen, so variable startAt is corrupted

function rtc2Date(dt){
  var t,d;
  d = dt.split(" ")[0]; t = dt.split(" ")[1];
  d = d.split("/"); t = t.split(":");
  return new Date(d[2] + 2000,d[1],d[0],t[0],t[1],t[2]);
}
var fs = require("fs");
var data = JSON.parse(fs.readFile("Juergen1_ctrl.json"));
var startAt = rtc2Date(data.options.startAt);
//console.log(startAt);
var entrys = fs.statSync("Juergen1_data.bin").size / 20;
console.log(startAt);

uncommented first console.log and it works fine:

function rtc2Date(dt){
  var t,d;
  d = dt.split(" ")[0]; t = dt.split(" ")[1];
  d = d.split("/"); t = t.split(":");
  return new Date(d[2] + 2000,d[1],d[0],t[0],t[1],t[2]);
}
var fs = require("fs");
var data = JSON.parse(fs.readFile("Juergen1_ctrl.json"));
var startAt = rtc2Date(data.options.startAt);
console.log(startAt);
var entrys = fs.statSync("Juergen1_data.bin").size / 20;
console.log(startAt);

Also had problems sometimes by using fs.statSync from terminal window. Connection to com-port was lost, and I had to reset and restart everything.
IMHO, this could be a problem around memory management for fs.statSync.
Using 1v80 on Espruino Board
Data returned from readFile is this:

{
  "tags": {
    "MQ2": "Methane, Butane, LPG, smoke",
    "MQ4": "Methane, CNG Gas",
    "MQ7": "Carbone Monoxide",
    "temp": "Temp",
    "rh": "Humidity"
   },
  "options": { "interval": 60000, "groupLength": 10,
    "startAt": "16/06/15 22:34:23"
   }
 }