This sounds like a backface-visibility problem. Make sure the following CSS is added to your divs:
'front' and 'back' divs: -webkit-backface-visibility: hidden;
'page' div: -webkit-transform-style: preserve-3d;
You'll get a nicer 3D transition if you add -webkit-perspective: 1000;
to whatever element that is wrapping 'page'.
Update: