Index: wp-admin/js/revisions.js
===================================================================
--- wp-admin/js/revisions.js	(revision 24705)
+++ wp-admin/js/revisions.js	(working copy)
@@ -43,7 +43,7 @@
 		},
 
 		initialize: function( options ) {
-			this.frame = options.frame;
+			this.frame     = options.frame;
 			this.revisions = options.revisions;
 
 			// Listen for changes to the revisions or mode from outside
@@ -131,7 +131,7 @@
 
 		initialize: function( options ) {
 			this.revisions = options.revisions;
-			this.slider = options.slider;
+			this.slider    = options.slider;
 
 			this.listenTo( this.slider, 'hovered:revision', this.updateRevision );
 			this.listenTo( this.slider, 'change:hovering', this.setHovering );
@@ -193,7 +193,7 @@
 	revisions.model.Diffs = Backbone.Collection.extend({
 		initialize: function( models, options ) {
 			_.bindAll( this, 'getClosestUnloaded' );
-			this.loadAll = _.once( this._loadAll );
+			this.loadAll   = _.once( this._loadAll );
 			this.revisions = options.revisions;
 			this.requests  = {};
 		},
@@ -277,7 +277,7 @@
 			if ( 'read' === method ) {
 				options = options || {};
 				options.context = this;
-				options.data = _.extend( options.data || {}, {
+				options.data    = _.extend( options.data || {}, {
 					action: 'get-revision-diffs',
 					post_id: revisions.settings.postId
 				});
@@ -323,7 +323,7 @@
 			this._debouncedEnsureDiff = _.debounce( this._ensureDiff, 200 );
 
 			this.revisions = options.revisions;
-			this.diffs = new revisions.model.Diffs( [], { revisions: this.revisions });
+			this.diffs     = new revisions.model.Diffs( [], { revisions: this.revisions });
 
 			// Set the initial diffs collection provided through the settings
 			this.diffs.set( revisions.settings.diffData );
@@ -384,9 +384,9 @@
 			var from, to, diffId, diff;
 
 			options = options || {};
-			from = this.get('from');
-			to = this.get('to');
-			diffId = ( from ? from.id : 0 ) + ':' + to.id;
+			from    = this.get('from');
+			to      = this.get('to');
+			diffId  = ( from ? from.id : 0 ) + ':' + to.id;
 
 			// Check if we're actually changing the diff id.
 			if ( this._diffId === diffId )
@@ -559,7 +559,7 @@
 		},
 
 		restoreRevision: function() {
-			var restoreUrl = this.model.get('to').attributes.restoreUrl.replace(/&/g, '&');
+			var restoreUrl    = this.model.get('to').attributes.restoreUrl.replace(/&/g, '&');
 			document.location = restoreUrl;
 		}
 	});
@@ -785,7 +785,7 @@
 			// Track the mouse position to enable smooth dragging,
 			// overrides default jQuery UI step behavior.
 			$( window ).on( 'mousemove.wp.revisions', { view: this }, function( e ) {
-				var view            = e.data.view,
+				var view              = e.data.view,
 					leftDragBoundary  = view.$el.offset().left, // Initial left boundary
 					sliderOffset      = leftDragBoundary,
 					sliderRightEdge   = leftDragBoundary + view.$el.width(),
@@ -909,7 +909,7 @@
 
 		updateUrl: function() {
 			var from = this.model.has('from') ? this.model.get('from').id : 0;
-			var to = this.model.get('to').id;
+			var to   = this.model.get('to').id;
 			if ( this.model.get('compareTwoMode' ) )
 				this.navigate( this.baseUrl( '?from=' + from + '&to=' + to ) );
 			else
Index: wp-admin/css/wp-admin.css
===================================================================
--- wp-admin/css/wp-admin.css	(revision 24705)
+++ wp-admin/css/wp-admin.css	(working copy)
@@ -3569,10 +3569,13 @@
 	-ms-transition:     opacity 0.5s;
 	-o-transition:      opacity 0.5s;
 	transition:         opacity 0.5s;
+	filter: alpha(opacity=0); /* ie8 and earlier */
 }
 
 .revisions.loading .loading-indicator {
 	opacity: 1;
+	filter: alpha(opacity=100); /* ie8 and earlier */
+
 }
 
 .revisions .diff {
@@ -3585,6 +3588,8 @@
 
 .revisions.loading .diff {
 	opacity: 0.5;
+	filter: alpha(opacity=50); /* ie8 and earlier */
+
 }
 
 .revisions-meta {