Session Expiring without any reason

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C#

ASP.NET

.NET

VS2010

.NET4

, +

Hi Everyone,
I have this problem with website application, coming to point, my exact problem is i get session expired and app pool recycled, which deletes all of my page progress and etc, firstly i was using my sign info in session, though now i am also storing it in cookies, so when the session expires, application restores the login info from cookies.

Session.Add("sUserID", src.userID);
Session.Add("suserLname", src.userLName);
Response.Cookies["abcdefCookie3"].Value = src.userID;
Response.Cookies["abcdefCookie3"].Expires = DateTime.Now.AddDays(1);
Response.Cookies["abcdefCookie4"].Value = src.userFName;
Response.Cookies["abcdefCookie4"].Expires = DateTime.Now.AddDays(1); 

but the other information like datatables in session, which of course gets lost with so called app pool recycling...

It Runs fine on LOCALHOST but on hosting services i have been facing this issue, i have these tried these hosters
1. One&One Website hosting
2. HostMySite
3. SiteGator
and
4. CreativeOn

i thought it might be overflowing memory with a lot of session variables so i deployed a middle page (navigator) in which i used following code

string frwdAdd = Request.QueryString["frwdAdd"];
string sUserID = (string)Session["sUserID"];
string suserLname = (string)Session["suserLname"];
Session.Clear();
Session.Add("sUserID",sUserID);
Session.Add("suserLname",suserLname);
Response.Redirect("~/" + frwdAdd, true);

using this i did get a little bit more time before session expired/app pool recycled, but eventually it expires...
so guys any hint, any link, any help would be appreciated A LOT.