The ticket #6412 (PROBLEM WITH FADEOUT ON IE8) was closed as invalid bug : "You can’t mix opacity and alpha-transparent images in IE unless you apply the opacity directly to an alpha-transparent <img> tag."

OK. But we use fadeOut or fadeTo to fade many divs and then fadeIn to get them normal.

I think it would be better not to use alpha filter when using fadeIn or fadeTo(1). It would be more natural for the programmer if the sequence fadeOut then fadeIn would leave things unchanged. This is not the case since the PNGs get broken in the process.

I made a correction in jQuery.cssHooks.opacity, set function :

var opacity = ( jQuery.isNaN(value) || value == 1 ) ? "" : "alpha(opacity=" + value * 100 + ")";

instead of

var opacity = jQuery.isNaN(value) ? "" : "alpha(opacity=" + value * 100 + ")"

Thank you.