I have been having this issue from a long time and would tell you that this has really been very annoying for me .The thing is that we have server that host site with multiple server. And the site uses both static and dynamic page. Now the dynamic page works perfect but static page didn't. We have two IPS in cluster mode. Right now we by pass IPS1 and static page work well when it reach IPS1. But the problem is that the Web pages go static when passed through IPS. So please do get back to me as I am waiting for the solutions.