invalid_grant: authentication failure

var oauth2 = {

  // NEW TEST ENVIRONMENT
  //loginUrl : 'https://ap2.salesforce.com', // /services/oauth2/token',
  //clientId : 'XXX',
  //clientSecret : 'XXX',
  //redirectUri : 'http://localhost'

  // SANDBOX
  loginUrl : 'https://cs87.salesforce.com', // /services/oauth2/token',
  clientId : 'XXX',
  clientSecret : 'XXX',
  redirectUri : 'http://localhost'

  // PROD
  //loginUrl : 'https://login.salesforce.com', // /services/oauth2/token',
  //clientId : 'XXX',
  //clientSecret : 'XXX',
  //redirectUri : 'http://localhost'

}



var config = {
  // NEW TEST
  //username : 'XXX@XX.com',
  //password : 'Password'

  // NEW TEST
  username : 'XXX@XX.com',
  password : 'Password' (Have tried combination of single password + with security token)

  // PROD
  //username : 'XXX@XXX.com',
  //password : PASSWORD+SecurityToken

}


app.get('/login', function(req, res) {

  var conn = new jsforce.Connection({
    oauth2
  });
  conn.login(config.username, config.password, function(err, userInfo) {
    if (err) { return console.error(err); }
    // Now you can get the access token and instance URL information.
    // Save them to establish connection next time.
    console.log(conn.accessToken);
    console.log(conn.instanceUrl);
    // logged in user property
    console.log("User ID: " + userInfo.id);
    console.log("Org ID: " + userInfo.organizationId);
  // ...
  });
});