Animate background-position works different on browsers

[plouf]

fiddle here - The goal is to make some perspective effect when scrolling, on background. It works ok on Chrome, on IE7, IE8, but:It works oddly on IE9 (background resets its position before \[code\]animation\[/code\])It does not work on Mozilla and Opera (scrolling is working but position of background not)It animates scrolling of page when mousewheel event is fired and it animates background position to move a little more than body is scrolling, what gives perspective feel)