Index: /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js
===================================================================
--- /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js	(revision 3674)
+++ /CKEditor/trunk/_source/plugins/wysiwygarea/plugin.js	(revision 3675)
@@ -418,7 +418,10 @@
 									setTimeout( function()
 										{
-											var $body = editor.document.$.body;
-											$body.runtimeStyle.marginBottom = '0px';
-											$body.runtimeStyle.marginBottom = '';
+											if ( editor.document )
+											{
+												var $body = editor.document.$.body;
+												$body.runtimeStyle.marginBottom = '0px';
+												$body.runtimeStyle.marginBottom = '';
+											}
 										}, 1000 );
 								}