While the cache inserts the user-agent header in the cache key, the ProducerFromFile does not. This causes the following bug: A sees an unmodified page B sees an unmodified page A modifies the .xml source for the page A sees a modified page B sees an unmodified page (when A and B use different browsers). The problem seems to be that the same instance of the producer, with its monitor, is used to validate the page. As ProducerFromFile was striping the user-agent, the second time ProducerFromFile inform that the cached version should be returned. This is part of a more general major misdesign in the cache. What I'm sending here is just a workaround. Please, CC-me the replies! Bye!