CSS background image rendering differently on iPhone

Question

We have a page design that works great in every PC browser that I have tried, but goes strange when viewed with an iPhone or iPod Touch.

The problem is something to

Answer 1

If you have kept

background-attachment: fixed;

in desktop CSS file, then remember it to change it to

background-attachment: scroll;

in mobile CSS file. If this is not done that it will show unexpected effect.