Got this tip from an episerver developer named Per Hassle: He had a problem with the cash getting emptied from time to time. The cause was that application domain recycled all the time. The problem was the virus program that scanned the site. It changed the .aspx, .ascx, .config, .dll files to modified . check this link for mor info: http://blogs.msdn.com/tess/archive/2006/08/02/asp-net-case-study-lost-session-variables-and-appdomain-recycles.aspx /Episerver Supportteam