Index: wp-includes/js/autosave.dev.js
===================================================================
--- wp-includes/js/autosave.dev.js	(revision 18462)
+++ wp-includes/js/autosave.dev.js	(working copy)
@@ -256,7 +256,9 @@
 		post_data["post_name"] = jQuery('#post_name').val();
 
 	// Nothing to save or no change.
-	if ( ( post_data["post_title"].length == 0 && post_data["content"].length == 0 ) || post_data["post_title"] + post_data["content"] == autosaveLast ) {
+	if ( ( (!post_data["post_title"] || (post_data["post_title"] && post_data["post_title"].length == 0)) && 
+			(!post_data["content"] || (post_data["content"] && post_data["content"].length == 0))) || 
+			post_data["post_title"] + post_data["content"] == autosaveLast ) {
 		doAutoSave = false;
 	}