So I used a machine key generation web app to generate a machineKey element. I then put it in the web.config in its appropriate spot. The server admin deployed to both servers and pointed the load balancer at them.
For whatever reason, when I go to the preprod load balanced site, it works fine. I login, do the stuff on site, all is well in the world. However, there is a user that repeatedly goes to the site and has issues where the symptom is session state being lost. I looked at his message and it is basically login succeeds, stores items in session state, redirects to a page, checks the items which come back as null and then gives he message.
Why am I not experiencing this but he is? More importantly, how do I make sure he doesn't keep losing session state?