Index: Commands.js
===================================================================
--- Commands.js	(revision 4707)
+++ Commands.js	(working copy)
@@ -39,7 +39,7 @@
 
 config.commands.cancelTiddler.handler = function(event,src,title)
 {
-	if(story.hasChanges(title) && !readOnly) {
+	if(!readOnly && (story.hasChanges(title) || !store.tiddlerExists(title) || store.isShadowTiddler(title))) {
 		if(!confirm(this.warning.format([title])))
 			return false;
 	}