Index: /CKEditor/trunk/CHANGES.html
===================================================================
--- /CKEditor/trunk/CHANGES.html	(revision 6583)
+++ /CKEditor/trunk/CHANGES.html	(revision 6584)
@@ -85,4 +85,5 @@
 		<li><a href="http://dev.ckeditor.com/ticket/6491">#6491</a> : Undesired image dialog dimension lock reset on url change.</li>
 		<li><a href="http://dev.ckeditor.com/ticket/7284">#7284</a> : [FF Quirks] Maximize now works correctly.</li>
+		<li><a href="http://dev.ckeditor.com/ticket/6609">#6609</a> : [IE9] Browser in high contrast mode is not properly detected.</li>
 		<li>Updated the following language files:<ul>
 			<li><a href="http://dev.ckeditor.com/ticket/7124">#7124</a> : Czech;</li>
Index: /CKEditor/trunk/_source/core/_bootstrap.js
===================================================================
--- /CKEditor/trunk/_source/core/_bootstrap.js	(revision 6583)
+++ /CKEditor/trunk/_source/core/_bootstrap.js	(revision 6584)
@@ -17,17 +17,8 @@
 	}
 
-	// Check is High Contrast is active by creating a temporary element with a
-	// background image.
-
-	var useSpacer = CKEDITOR.env.ie && CKEDITOR.env.version < 7,
-		useBlank = CKEDITOR.env.ie && CKEDITOR.env.version == 7;
-
-	var backgroundImageUrl = useSpacer ? ( CKEDITOR.basePath + 'images/spacer.gif' ) :
-							 useBlank ? 'about:blank' : 'data:image/png;base64,';
-
+	// Check whether high contrast is active by creating a colored border.
 	var hcDetect = CKEDITOR.dom.element.createFromHtml(
-		'<div style="width:0px;height:0px;' +
-			'position:absolute;left:-10000px;' +
-			'background-image:url(' + backgroundImageUrl + ')"></div>', CKEDITOR.document );
+		'<div style="width:0px;height:0px;position:absolute;left:-10000px;' +
+			'border: 1px solid;border-color: red blue;"></div>', CKEDITOR.document );
 
 	hcDetect.appendTo( CKEDITOR.document.getHead() );
@@ -37,5 +28,5 @@
 	try
 	{
-		CKEDITOR.env.hc = ( hcDetect.getComputedStyle( 'background-image' ) == 'none' );
+		CKEDITOR.env.hc = hcDetect.getComputedStyle( 'border-top-color' ) == hcDetect.getComputedStyle( 'border-right-color' );
 	}
 	catch (e)