Do I get this right, you are using the optional Parent parameter when you create the entity? Because if you do that, the entity will use the parents attributes (scale, position etc.). But if you first create the entity without any parent, and then after all settings parent it to the parent, using "ParentEntity child, parent", this shouldn't happen. Just make sure not to edit scale or anything of the parent after that unless you want the children to be scaled etc. too.
(BTW semar, if you are still using that particle engine, I have to confess, it pretty tricky sometimes because there are two parameters for speed, one is th growing speed that will be used to fade multiple growing sprites, and the other one named livespan is the number of such growing cycles (see min size and max size). So live span is actually dependent of the the growing speed. Today I'd rather suggest to divide the livespan through the growing speed inside the function to make it more useable because this way the livespan will be more accurate.)
(BTW semar, if you are still using that particle engine, I have to confess, it pretty tricky sometimes because there are two parameters for speed, one is th growing speed that will be used to fade multiple growing sprites, and the other one named livespan is the number of such growing cycles (see min size and max size). So live span is actually dependent of the the growing speed. Today I'd rather suggest to divide the livespan through the growing speed inside the function to make it more useable because this way the livespan will be more accurate.)