CI session automatically destroy

[eluser]Unknown[/eluser]
Hello Everyone.

I am using CI session class. It was working fine but suddenly working very strange. When i logged in on login page, after login page redirect to home page.

I can see the session on home page [I have printed the session variable]. When I click on any other page even the home page again, the session destroy.

Session data exist in database but not in browser session.

Please help

Thanks