Sometimes we find png image is now showing properly on IE. i.e its transparent property do not get apply.
To solve do the following fix (microsoft Alphaimage filter)
.png-background{
background: url(“/path/to/image/source/ong-image.png”) no-repeat scroll transparent;
height: n1px;
width: n2px
_background-image: none;
_filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src=/path/to/image/source/ong-image.png,sizingMethod=’scale’);
}