A simple solution for IE6 PNG support is
HTML Code:
< div class="iePng_logo" id="ieBg"> <img src="images/logo_png.png" class="ieHide" /> </div>

CSS Code:
.iePng_logo {filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='images/logo_png.png',sizingMethod='scale'); width:307px; height:34px;}
.iePng {filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(src='images/screenshot.png',sizingMethod='scale'); width:438px; height:230px;}
.ieHide {border:0 solid #fff; _display:none;}
#ieBg {border:0;}

You can check its working demo from the following URL, Check top left logo in all browsers its transparent PNG, you can save it and check its transparency
http://expertsdesk.net/novotech/