*/
<!--[if lt IE 7]>
	<script defer type="text/javascript" src="js/pngfix.js"></script>
	<link rel="stylesheet" href="http://imperialcode.com/css/ie_styles.css" type="text/css" media="screen" />
	<![endif]-->
/*

#footerLinksInner ul.links li.linksHeaderBlog {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/pencil.png, sizingMethod=crop);
}

#footerAchat {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/glass_block.png, sizingMethod=image);
}

#recentActivity ul li.new {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_new.png, sizingMethod=crop);
	}
	
.listing .image.new {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_new_medium.png, sizingMethod=crop);
	}

*/
<!--[if lt IE 7]>
	<script defer type="text/javascript" src="js/pngfix.js"></script>
	<link rel="stylesheet" href="ie_styles.css" type="text/css" media="screen" />
	<![endif]-->
/*

#footerLinksInner ul.links li.linksHeaderBlog {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/pencil.png, sizingMethod=crop);
}

#footerAchat {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/glass_block.png, sizingMethod=image);
}

#recentActivity ul li.new {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_new.png, sizingMethod=crop);
	}
	
.listing .image.new {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_new_medium.png, sizingMethod=crop);
	}

#footerLinksInner ul.links li.linksHeaderBlog {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/pencil.png, sizingMethod=crop);
}
#footerLinksInner ul.links li.linksHeaderTools {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/tools.png, sizingMethod=crop);
}
#footerAchat {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/glass_block.png, sizingMethod=image);
}
#arbresLogo {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/100_arbres.png, sizingMethod=image);
}
.questionBubble {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/question_bubble.png, sizingMethod=image);
}
.innerFormBlock{
		background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/vue_Liste_index.png, sizingMethod=image);
}

#recentActivity ul li.new {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_new.png, sizingMethod=crop);
	}
	
#recentActivity ul li.openhouse {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_openhouse.png, sizingMethod=crop);
	}
	
#recentActivity ul li.prestige {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_prestige.png, sizingMethod=crop);
	}
	
#recentActivity ul li.sold {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_sold.png, sizingMethod=crop);
	}
	
#recentActivity ul li.active {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_active.png, sizingMethod=crop);
	}

.listing .image.new {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_new_medium.png, sizingMethod=crop);
	}
	
.listing .image.sold {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_sold_medium.png, sizingMethod=crop);
	}
	
.listing .image.prestige {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_prestige_medium.png, sizingMethod=crop);
	}
	
.listing .image.openhouse {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_openhouse_medium.png, sizingMethod=crop);
	}

.listing .image.active {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_active_medium.png, sizingMethod=crop);
	}

#propertyImage.new {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_new_large.png, sizingMethod=crop);
	}

#propertyImage.openhouse {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_openhouse_large.png, sizingMethod=crop);
	}

#propertyImage.prestige {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_prestige_large.png, sizingMethod=crop);
	}

#propertyImage.sold {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_sold_large.png, sizingMethod=crop);
	}
#propertyImage.active {
	background: none;
	filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(enabled=true, src=images/image_tab_active_large.png, sizingMethod=crop);
	}

#leftBlock img.onglet {
	margin-bottom: 0px;
	margin-left: 0px;
}
#leftBlock img.ongletfirst {
	margin-bottom: 0px;
	margin-left: 0px;
}

h1.headline { font-size: 2.5em;
	margin: 28px 0 21px 40px;
}

.formBlock {
	width: 430px;
	border: 1px solid #d6d6d6;
	background: url(images/yellow_bar_bg.jpg) 0 0;
	margin: -10px 0 16px;
}

http://imperialcode.com/css/ie_styles.css

Fix probleme de transparence avec le background sous iE. Pour "crop" ou "image".

Fix iE Background Transparence: ie_style.css

ie, textmate, background

CSS