asp.net web.config timeouts

Here is a snippet from my web.config file:

<system.web>
  <sessionState timeout="1440"></sessionState>
  <authentication mode="Forms">
    <forms loginUrl="~/Account/LogOn" timeout="1440" 
             cooki开发者_如何学Goeless="UseCookies" 
             />
  </authentication>

I am getting sessions expiring much sooner than 1 day (within an hour or so). Are there any other IIS or ASP.NET settings that could be affecting this? (the app is not setting any timeouts from code).

I would check the application pools recycle time. This is probably the cause as I think that it defaults to something like 20 minutes.