DigitalPulse() on 1V66

Am I doing something wrong here.

//test_puls01

var thePin = LED1;
var theDummy = LED2;

/*
// Both turn on at the same time, then LED2 off, and then LED1 off.
  digitalPulse(thePin,1,800);
  digitalPulse(theDummy,1,400);
// This is normal.
*/

// First turn LED1 on, then LED2 on, and off almost simultaneously.
  digitalPulse(thePin,1,800);
  digitalPulse(thePin,0,0);
  digitalPulse(theDummy,1,400);
// Something wrong here


/* _____                 _
|   __|___ ___ ___ _ _|_|___ ___
|   __|_ -| . |  _| | | |   | . |
|_____|___|  _|_| |___|_|_|_|___|
          |_| http://espruino.com
 1v66 Copyright 2014 G.Williams
>echo(0);
=undefined
Uncaught [object Object]
 at line 1 col 26
  digitalPulse(thePin,0,0);
                          ^
> 
*/