because of this , when page's height over screen size, the action will be 

jump to top -> page change

and the animation is ugly for android 2.2(medias) and 2.3(xperia arc) 

when i do a page change ( page A -> page B ) with silde, the real action is below

page A -> page A jump to top -> page B -> page A (with page B bottom) -> page B

any suggestion ?