Trouble with particles after updating to 5.3

So I just updated to unity 5.3 and suddenly most of my particles either stopped working or have weird behaviour. The Stop() and Play() function in ParticleSystem works only sometimes and ParticleSystem.isPlaying along with ParticleSystem.isStopped always return the same value.

void Update() {
	if (Input.GetKeyDown (KeyCode.E)) {	
		normalExhaust.Play ();
		Debug.Log (normalExhaust.isPlaying); // returns true
		Debug.Log (normalExhaust.isPlaying); // returns true

Here’s a piece of code that shows my problem. I am certain that no other script is interacting with the particle system. Every particle system in my scene only plays if I set it to Play on Awake and if i pause it after that it cannot be played again. 60592-snap.jpg
Here’s a snapshot of my particle settings, in case you think the problem comes from there.

Is this a bug from the new version or have I messed something up? I tried testing the behaviour of the particles in empty scenes and with only one script attached and seem to get the same problems.
Thanks in advance for the help!

here try this and put it on the particle system!
I’ve never been able to use “”

 var Par : ParticleSystem;
    function Start () {
     Par = GetComponent(ParticleSystem);
    function Update () {
    if (Input.GetKey(KeyCode.DownArrow)))
    Par.emissionRate = 55; // how many particles you want!
    } else {
    Par.emissionRate = 0;