I have this website which hosted on a server in IIS 7. Its an asp.net website and involves huge trasactions on daily basis. For the last 2 years it worked like a charm but recently it's been exhibiting some problems like not getting logged in, abnormally/abruptly time out before it's set time etc. We rebuild the indexes and it started working fine except for one problem i.e. SESSION TIMEOUT before it's set time i.e. i have set 30 mins in web.config and it sometimes can remain idle for 30 mins, yes it does, ok but most of the time it expires in 10 min, or 5 min or any mins. WHY ? we can't figure out why ?