Timeout with the new Identity Framework

I am  using the new 4.5 Identity Framework and I have set
<authentication mode="Forms"> <forms loginUrl="~/Account/Login.aspx" timeout="1" defaultUrl="~/" cookieless="UseCookies" requireSSL="true" path="/MyApplication" /> </authentication> I set the timeout for 1 on the testing evironment to test the time out.  So far the application will never timeout.
I am also having a issue with the back button.  If I login and then after a few screens I use the back button all the way back to the LoginScreen I cn hit forward and go back into the application.  Is there a way that if th e user clicks the back button all the way to the login screen that it will force a logout?