Index: NewTiddler.js
===================================================================
--- NewTiddler.js	(revision 7991)
+++ NewTiddler.js	(working copy)
@@ -49,7 +49,7 @@
 	if(customFields)
 		story.addCustomFields(tiddlerElem,customFields);
 	var text = this.getAttribute("newText");
-	if(typeof text == "string")
+  if(typeof text == "string" && story.getTiddlerField(title, "text"))
 		story.getTiddlerField(title,"text").value = text.format([title]);
 	for(var t=0;t<tags.length;t++)
 		story.setTiddlerTag(title,tags[t],+1);