diff --git a/src/jquery/coreTest.js b/src/jquery/coreTest.js
index 4370e9da8..896130011 100644
--- a/src/jquery/coreTest.js
+++ b/src/jquery/coreTest.js
@@ -261,9 +261,9 @@ test("css(String|Hash)", function() {
 	
 	$.each("0,0.25,0.5,0.75,1".split(','), function(i, n) {
 		$('#foo').css({opacity: n});
-		ok( $('#foo').css('opacity') == n, "Assert opacity is " + n + " as a String" );
+		ok( $('#foo').css('opacity') == parseFloat(n), "Assert opacity is " + parseFloat(n) + " as a String" );
 		$('#foo').css({opacity: parseFloat(n)});
-		ok( $('#foo').css('opacity') == n, "Assert opacity is " + n + " as a Number" );
+		ok( $('#foo').css('opacity') == parseFloat(n), "Assert opacity is " + parseFloat(n) + " as a Number" );
 	});	
 	$('#foo').css({opacity: ''});
 	ok( $('#foo').css('opacity') == '1', "Assert opacity is 1 when set to an empty String" );
@@ -288,9 +288,9 @@ test("css(String, Object)", function() {
 	
 	$.each("0,0.25,0.5,0.75,1".split(','), function(i, n) {
 		$('#foo').css('opacity', n);
-		ok( $('#foo').css('opacity') == n, "Assert opacity is " + n + " as a String" );
+		ok( $('#foo').css('opacity') == parseFloat(n), "Assert opacity is " + parseFloat(n) + " as a String" );
 		$('#foo').css('opacity', parseFloat(n));
-		ok( $('#foo').css('opacity') == n, "Assert opacity is " + n + " as a Number" );
+		ok( $('#foo').css('opacity') == parseFloat(n), "Assert opacity is " + parseFloat(n) + " as a Number" );
 	});
 	$('#foo').css('opacity', '');
 	ok( $('#foo').css('opacity') == '1', "Assert opacity is 1 when set to an empty String" );
diff --git a/src/jquery/jquery.js b/src/jquery/jquery.js
index 30396cacc..84a159433 100644
--- a/src/jquery/jquery.js
+++ b/src/jquery/jquery.js
@@ -1403,8 +1403,10 @@ jQuery.extend({
 	curCSS: function(elem, prop, force) {
 		var ret;
 
-		if (prop == "opacity" && jQuery.browser.msie)
-			return jQuery.attr(elem.style, "opacity");
+		if (prop == "opacity" && jQuery.browser.msie) {
+			ret = jQuery.attr(elem.style, "opacity");
+			return ret == "" ? "1" : ret;
+		}
 		
 		if (prop == "float" || prop == "cssFloat")
 			prop = jQuery.browser.msie ? "styleFloat" : "cssFloat";
@@ -1537,7 +1539,7 @@ jQuery.extend({
 			}
 
 			return elem.filter ? 
-				(parseFloat( elem.filter.match(/opacity=([^)]*)/)[1] ) / 100).toString() : "1";
+				(parseFloat( elem.filter.match(/opacity=([^)]*)/)[1] ) / 100).toString() : "";
 		}
 		
 		// Certain attributes only work when accessed via the old DOM 0 way