setParticleParams seems to somehow break down if applied twice on same emitter; for example if you first set the class "BigDestructionSmoke" for an emitter, then later for the same emitter set some params for another effect and you will get something completely different than you might expect, like squares with numbers, bubbles, etc instead of a fire.
setParticleClass is affected as well, if you set the class "BigDestructionSmoke" for an emitter, then set "BigDestructionFire" for the same emitter squares, bubbles etc. appear instead of the fire..