Index: jquery-1.3.1.js
===================================================================
--- jquery-1.3.1.js	(official version)
+++ jquery-1.3.1-ie-opacity-bugfix.js
@@ -772,8 +772,10 @@
 		// We need to handle opacity special in IE
 		if ( name == "opacity" && !jQuery.support.opacity ) {
 			ret = jQuery.attr( style, "opacity" );
-
-			return ret == "" ?
+			if (ret == '') {
+				ret = jQuery.curCSS(elem, 'filter').match(/opacity=(\d+)/) ? RegExp.$1/100 : '';
+			}
+			return ret === "" ?
 				"1" :
 				ret;
 		}