Index: /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js	(revision 6436)
+++ /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js	(revision 6437)
@@ -1097,7 +1097,7 @@
 				});
 
-			// IE8 stricts mode doesn't have 'contentEditable' in effect
+			// IE>=8 stricts mode doesn't have 'contentEditable' in effect
 			// on element unless it has layout. (#5562)
-			if ( CKEDITOR.env.ie8Compat )
+			if ( CKEDITOR.document.$.documentMode >= 8 )
 			{
 				editor.addCss( 'html.CSS1Compat [contenteditable=false]{ min-height:0 !important;}' );