w3 page minify was minifying the add_new_events.js. You need to add a ; after the regex string for this plugin to work correctly:
var isUrl = function( s ) {
var regexp = /(http|https|webcal):\/\/(\w+:{0,1}\w*@)?(\S+)(:[0-9]+)?(\/|\/([\w#!:.?+=&%@!\-\/]))?/;
return regexp.test(s);
};without that ; after the regex var it gets compressed to ?/return and that isn't a valid regex string expression
http://wordpress.org/extend/plugins/all-in-one-event-calendar/
