Why are the last 2 chars of my NodeJS shred POST request getting stripped?

I am having a problem submitting a UTF8 encoded text file in a POST request using NodeJS "shred"

The text content I am trying to post looks fine on the client side, I know because I console.log it to the screen just before calling client.post, what the server gets is the content of the text file but the last 2 chars are always missing/chopped. This is not a problem with ANSI text files. If I convert the textfile from UTF8 to ANSI, it is complete when it reaches the server.

var Shred = require('shred');
var client = new Shred();
var textToPost = fs.readFileSync("myfile.txt", 'utf8');
console.log (textToPost);
client.post({
     url: "http://www.example.com/readTextFile.php",
     headers: { 'Content-Type': 'application/x-subrip'},
content: textToPost,
on: {
  200: function (response) {
    console.log("posted ok");
console.log(response.content.body);
  },
  500: function (response) {
    asyncCb(new Error('bad response\n' + response.content.body));
  }
}

What is recieved on the server (by readTextFile.php) is the contents of myfile.txt with the last 2 chars stripped out. I cannot understand why. This has big downstream implications so any patchy workarounds are not likely to help.

I also noticed that when the contents of textToPost are logged to the console, there is a "?" preceding the contents. This doesn't appear when the file is an ANSI encoded file.

Please help.. thank you