Jerky scene running

Hi guys,
i have problem of scene running jurkey.
My game has 5 different level.In that only first two level running jerky after that all level running smoothly.
I am used same textures,scripting in all levels.
In computer all levels run smoothly but in ipad first two level running jerky.
please help me on this.
Thanks in advanced.

more information please, currently too vague to be of any use for people willing to help you

one camera(follow the ball),3d object as a stage,one ball as a character and 10 stars(with animation) including in the scene.