Particle system pauses when off-screen

I’ve noticed that in my version of Unity 4.0.0f7, shuriken particle systems pause themselves when they are off-screen (i.e. not in the main camera frustum).

So, for instance, if I spawn an explosion behind the camera, then after a pause I turn the camera round, the explosion only begins playing as it comes into shot.

I assume this is a way of conserving CPU time as off-screen particles do not get played. But is there a way to turn this “feature” off?

I noticed the same behaviour on child emitters, when the Duration setting on the parent emitter is greater, than that on the children.
So, it may help to check that.

I have seen that too, I’m using a pool for ParticleSystem, and after several times, the re-used ParticleSystem will start to pause when offscreen, not sure why.