catch 400 response from Google and clearly indicate that the spreadsheet URL is bad or it's not public

source/js/VMM.Timeline.DataObj.js

@@ -200,6 +200,11 @@ if (typeof VMM.Timeline !== 'undefined' && typeof VMM.Timeline.DataObj == 'undef
 							VMM.Timeline.DataObj.model.googlespreadsheet.buildData(d);
 						})
 							.error(function(jqXHR, textStatus, errorThrown) {
+								if (jqXHR.status == 400) {
+									VMM.fireEvent(global, VMM.Timeline.Config.events.messege, "Error reading Google spreadsheet. Check the URL and make sure it's published to the web.");
+									clearTimeout(timeout);
+									return;
+								}
 								trace("Google Docs ERROR");
 								trace("Google Docs ERROR: " + textStatus + " " + jqXHR.responseText);
 							})