Index: /Users/denis/Sites/sem-pro/wp-includes/js/thickbox/thickbox.css
===================================================================
--- /Users/denis/Sites/sem-pro/wp-includes/js/thickbox/thickbox.css	(revision 630)
+++ /Users/denis/Sites/sem-pro/wp-includes/js/thickbox/thickbox.css	(working copy)
@@ -33,6 +33,7 @@
 .TB_overlayMacFFBGHack {background: url(macFFBgHack.png) repeat;}
 .TB_overlayBG {
 	background-color:#000;
+	-ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=75)"; // first!
 	filter:alpha(opacity=75);
 	-moz-opacity: 0.75;
 	opacity: 0.75;