Index: src/offset.js
===================================================================
--- src/offset.js	(revision 5084)
+++ src/offset.js	(working copy)
@@ -10,7 +10,7 @@
 		    offsetParent = elem.offsetParent, 
 		    doc          = elem.ownerDocument,
 		    safari2      = safari && parseInt(version) < 522 && !/adobeair/i.test(userAgent),
-		    fixed        = jQuery.css(elem, "position") == "fixed";
+		    fixed        = jQuery.curCSS(elem, "position") == "fixed";
 	
 		// Use getBoundingClientRect if available
 		if ( elem.getBoundingClientRect ) {
@@ -45,7 +45,7 @@
 					border( offsetParent );
 					
 				// Add the document scroll offsets if position is fixed on any offsetParent
-				if ( !fixed && jQuery.css(offsetParent, "position") == "fixed" )
+				if ( !fixed && jQuery.curCSS(offsetParent, "position") == "fixed" )
 					fixed = true;
 			
 				// Set offsetChild to previous offsetParent unless it is the body element
@@ -57,12 +57,12 @@
 			// Get parent scroll offsets
 			while ( parent && parent.tagName && !/^body|html$/i.test(parent.tagName) ) {
 				// Remove parent scroll UNLESS that parent is inline or a table to work around Opera inline/table scrollLeft/Top bug
-				if ( !/^inline|table.*$/i.test(jQuery.css(parent, "display")) )
+				if ( !/^inline|table.*$/i.test(jQuery.curCSS(parent, "display")) )
 					// Subtract parent scroll offsets
 					add( -parent.scrollLeft, -parent.scrollTop );
 			
 				// Mozilla does not add the border for a parent that has overflow != visible
-				if ( mozilla && jQuery.css(parent, "overflow") != "visible" )
+				if ( mozilla && jQuery.curCSS(parent, "overflow") != "visible" )
 					border( parent );
 			
 				// Get next parent
@@ -71,8 +71,8 @@
 		
 			// Safari <= 2 doubles body offsets with a fixed position element/offsetParent or absolutely positioned offsetChild
 			// Mozilla doubles body offsets with a non-absolutely positioned offsetChild
-			if ( (safari2 && (fixed || jQuery.css(offsetChild, "position") == "absolute")) || 
-				(mozilla && jQuery.css(offsetChild, "position") != "absolute") )
+			if ( (safari2 && (fixed || jQuery.curCSS(offsetChild, "position") == "absolute")) || 
+				(mozilla && jQuery.curCSS(offsetChild, "position") != "absolute") )
 					add( -doc.body.offsetLeft, -doc.body.offsetTop );
 			
 			// Add the document scroll offsets if position is fixed
Index: src/core.js
===================================================================
--- src/core.js	(revision 5084)
+++ src/core.js	(working copy)
@@ -611,6 +611,8 @@
 
 // exclude the following css properties to add px
 var exclude = /z-?index|font-?weight|opacity|zoom|line-?height/i;
+//cache this
+var CS = document.defaultView && document.defaultView.getComputedStyle;
 
 jQuery.extend({
 	noConflict: function( deep ) {
@@ -838,7 +840,7 @@
 			if ( !jQuery.browser.safari )
 				return false;
 
-			var ret = document.defaultView.getComputedStyle( elem, null );
+			var ret = CS( elem, null );
 			return !ret || ret.getPropertyValue("color") == "";
 		}
 
@@ -864,7 +866,7 @@
 		if ( !force && elem.style && elem.style[ name ] )
 			ret = elem.style[ name ];
 
-		else if ( document.defaultView && document.defaultView.getComputedStyle ) {
+		else if ( CS ) {
 
 			// Only "float" is needed here
 			if ( name.match( /float/i ) )
@@ -872,7 +874,7 @@
 
 			name = name.replace( /([A-Z])/g, "-$1" ).toLowerCase();
 
-			var getComputedStyle = document.defaultView.getComputedStyle( elem, null );
+			var getComputedStyle = CS( elem, null );
 
 			if ( getComputedStyle && !color( elem ) )
 				ret = getComputedStyle.getPropertyValue( name );