Index: /CKEditor/trunk/_source/plugins/styles/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/styles/plugin.js	(revision 5630)
+++ /CKEditor/trunk/_source/plugins/styles/plugin.js	(revision 5631)
@@ -1,3 +1,3 @@
-/*
+/*
 Copyright (c) 2003-2010, CKSource - Frederico Knabben. All rights reserved.
 For licensing, see LICENSE.html or http://ckeditor.com/license
@@ -61,5 +61,5 @@
 						// Save the current state, so it can be compared next
 						// time.
-						callback.state !== currentState;
+						callback.state = currentState;
 					}
 				}
@@ -67,5 +67,5 @@
 	}
 
-	// Save the callback info, so it can be checked on the next occurence of
+	// Save the callback info, so it can be checked on the next occurrence of
 	// selectionChange.
 	styleStateChangeCallbacks.push( { style : style, fn : callback } );
@@ -181,4 +181,8 @@
 		},
 
+		/**
+		 * Whether this style can be applied at the element path.
+ 		 * @param elementPath
+		 */
 		checkApplicable : function( elementPath )
 		{
@@ -223,4 +227,6 @@
 
 						var elementAttr = element.getAttribute( attName ) || '';
+
+						// Special treatment for 'style' attribute is required.
 						if ( attName == 'style' ?
 							compareCssText( attribs[ attName ], normalizeCssText( elementAttr, false ) )
@@ -1199,4 +1205,5 @@
 	}
 
+	// Make the comparison of attribute value easier by standardizing it.
 	function normalizeProperty( name, value, isStyle )
 	{
@@ -1206,4 +1213,5 @@
 	}
 
+	// Make the comparison of style text easier by standardizing it.
 	function normalizeCssText( unparsedCssText, nativeNormalize )
 	{
@@ -1241,4 +1249,10 @@
 	}
 
+	/**
+	 * Compare two bunch of styles, with the speciality that value 'inherit'
+	 * is treated as a wildcard which will match any value.
+	 * @param {Object|String} source
+	 * @param {Object|String} target
+	 */
 	function compareCssText( source, target )
 	{
@@ -1247,6 +1261,4 @@
 		for( var name in source )
 		{
-			// Value 'inherit'  is treated as a wildcard,
-			// which will match any value.
 			if ( !( name in target &&
 					( target[ name ] == source[ name ]