How to Simulate background-attachment iPad
===

I'm developing an Asp.Net MVC site with jQuery Mobile.
I've this CSS part to set the background image to be fixed in the center of the site while scrolling:

    background: white url(Image/A-HD.jpg);
    background-repeat: no-repeat;
    background-position: 50% 50%; /*or center center */
    background-attachment: fixed;
    background-size: 50%;

It works everywhere, except for the iPad 2 (the one iOS I tested). Seems like **background-attachment: fixed;** doesn't work properly: the background image actually stays in the center, but doesn't follow my scroll.

So, is there a way to simulate *background-attachment: fixed;* for iPad2 (and similar, I suppose)?

Thanks!