Index: _source/skins/kama/skin.js
===================================================================
--- _source/skins/kama/skin.js	(revision 5301)
+++ _source/skins/kama/skin.js	(working copy)
@@ -104,7 +104,7 @@
 
 			function updateStylesheets( styleNodes, styleContent, replace )
 			{
-				var r, i, content;
+				var r, i, content, node;
 				for ( var id  = 0 ; id < styleNodes.length ; id++ )
 				{
 					if ( CKEDITOR.env.webkit )
@@ -121,13 +121,23 @@
 					else
 					{
 						content = styleContent;
+						node = styleNodes[ id ].$;
 						for ( r  = 0 ; r < replace.length ; r++ )
 							content = content.replace( replace[ r ][ 0 ], replace[ r ][ 1 ] );
 
 						if ( CKEDITOR.env.ie )
-							styleNodes[ id ].$.styleSheet.cssText += content;
+						{
+							// IE returns unescaped selectors #5045
+							var current = node.styleSheet.cssText
+								.replace( /.cke_editor_([^\s]*)/g , function( str, patt )
+								{
+									return '.cke_editor_' + CKEDITOR.tools.escapeCssSelector( patt );
+								} );
+
+							node.styleSheet.cssText = current + content;
+						}
 						else
-							styleNodes[ id ].$.innerHTML += content;
+							node.innerHTML += content;
 					}
 				}
 			}