How do I control the frames of sprite sheets? I have the basics down for importing and using a PNG as an animation base. But I am having problems with the animation running in the back ground. 

I am using this for a dialogue box and was hoping to be able to use the scene.addObjects("mydiobox" , reference.point) function to simply have all the letters spelled out in an animation, but it is running in the other layer and comes in in the middle of the animation. Is there a way to decide what frame it comes in on?
You can specify the start frame in the Image Editor:

If it's coming in in the middles of that animation, we have another problem, because when an object is in a hidden layer, it should not be playing. So this is a bug or something, sorry.