Jun 09, 2011 08:51 AM|Robertdennyson|LINK
Probably has nothing to do with the session but with where the session is stored. By default session is stored in same process (InProc) as application is thus whenever the application pool restarts session is lost. To workaround it you can either save the
session state on SQL server or OutOfProc mode which allows you to run separate process on Windows which will only store sessions and will be never recycled without the timeout limits are met.