Irina

.logo {
height: 44px; width: 300px;
background: url(../../Images/logo.png) no-repeat;
_behavior: expression( /* IE6 only – transparency with proper handling of relative URLs */
this.src = this.src ? this.src : this.currentStyle.backgroundImage.split(’”‘)[1],
this.style.background = “none”,
this.style.filter = “progid:DXImageTransform.Microsoft.AlphaImageLoader(src=” + this.src + “)”);
}

Or in the head tag of the html page, you had to put this code

<!–[if lt IE 7]>
<style type=”text/css”>
.download_leftsidebar_back {
background-image: none !important;
filter: progid:DXImageTransform.Microsoft.AlphaImageLoader
(sizingMethod=scale, src=’App_Themes/Default/images/download_leftsidebar_back.png’) ;

}
</style>
<![endif]–v

And i saw another very good idea http://www.komodomedia.com/blog/2007/11/css-png-image-fix-for-ie/