Change ParticleEffect programmatically

While some Effect paramenters look to feed the emiter by the pointer kept to the effect and would apply instantly…

This is not taking effect for me:

particleFlareEffect_->SetMinDirection (Vector3::DOWN);
particleFlareEffect_->SetMaxDirection (Vector3::DOWN * 20);
particleFlareEmitter_->ApplyEffect();

But some other parameters are (Numparticles) ApplyEffect

    particleFlareEffect_->SetNumParticles(100);
    particleFlareEmitter_->ApplyEffect();

Additionally if you change some effect parameters programatically, and you set it again(SetEffect), The function silently would return without affecting the particle (as the pointer of the object would be the same).

I have been struggling changing the direction of an emission. At the end just changing the numparticles (from the Emiter) worked for me, but tried many other changes from the Effect unsuccessfully.

Also I see parameters under a xml <particleemitter> tag and others in a <particleeffect>

What is the procedure of changing an ongoing ParticleEmmiter Effect?