I'm having a problem with the url rewriting when doing ajax-postbacks in an update panel. The browser's address is - http://localhost/en/ ..and I do a postback in an updatepanel The first time around the AJAX request is issued against: - http://localhost/en/ ..and request works as expected. On the second AJAX postback the request is issued against - http://localhost/en/default.aspx?id=3&epslanguage=en ..which cannot be found and I get a 404 Any suggestions? I was hoping for someone to hint at a solution or workaround to my problem.