Index: /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js	(revision 4517)
+++ /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js	(revision 4518)
@@ -645,23 +645,35 @@
 	if( CKEDITOR.env.gecko )
 	{
-		var topBody = new CKEDITOR.dom.element( window.top.document.body );
-		topBody.setAttribute( 'onpageshow', topBody.getAttribute( 'onpageshow' ) 
-				+ ';event.persisted && CKEDITOR.tools.callFunction(' +
-				CKEDITOR.tools.addFunction( function()
-				{
-					var allInstances = CKEDITOR.instances,
-						editor,
-						doc;
-					for( var i in allInstances )
-					{
-						editor = allInstances[ i ];
-						doc = editor.document;
-						if( doc )
-						{
-							doc.$.designMode = 'off';
-							doc.$.designMode = 'on';
-						}
-					}
-				} ) + ')' );
+		var topWin = window.top;
+
+		( function ()
+		{
+			var topBody = topWin.document.body;
+
+			if( !topBody )
+				topWin.addEventListener( 'load', arguments.callee, false );
+			else
+			{
+				topBody.setAttribute( 'onpageshow', topBody.getAttribute( 'onpageshow' )
+						+ ';event.persisted && CKEDITOR.tools.callFunction(' +
+						CKEDITOR.tools.addFunction( function()
+						{
+							var allInstances = CKEDITOR.instances,
+								editor,
+								doc;
+							for( var i in allInstances )
+							{
+								editor = allInstances[ i ];
+								doc = editor.document;
+								if( doc )
+								{
+									doc.$.designMode = 'off';
+									doc.$.designMode = 'on';
+								}
+							}
+						} ) + ')' );
+			}
+		} )();
+
 	}
 })();