Unable to make the session state request to

[Not Liking Dot Net Today]

During high usage periods I am getting

Stack trace below:
System.Web.HttpException: Unable to make the session state request to
the session state server. Please ensure that the ASP.NET State service
is started and that the client and server ports are the same. If the
server is on a remote machine, please ensure that it accepts remote
requests by checking the value of
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\aspnet_state\Parameters\AllowRemoteConnection.
at System.Web.SessionState.OutOfProcStateClientManager.MakeRequest(StateProtocolVerb
verb, String id, StateProtocolExclusive exclusiveAccess, Int32
timeout, Int32 lockCookie, Byte[] buf, Int32 cb, Int32 networkTimeout,
SessionNDMakeRequestResults& results)
at System.Web.SessionState.OutOfProcStateClientManager.DoGet(String
id, StateProtocolExclusive exclusiveAccess)
at System.Web.SessionState.OutOfProcStateClientManager.GetExclusive(String
id)
at System.Web.SessionState.OutOfProcStateClientManager.System.Web.SessionState.IStateClientManager.BeginGetExclusive(String
id, AsyncCallback cb, Object state)
at System.Web.SessionState.SessionStateModule.GetSessionStateItem()
at System.Web.SessionState.SessionStateModule.BeginAcquireState(Object
source, EventArgs e, AsyncCallback cb, Object extraData)
at System.Web.AsyncEventExecutionStep.System.Web.HttpApplication+IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step,
Boolean& completedSynchronously

my configuration is three web servers in a webfarm all saving state to
a forth system.

The system seems to work fine when I have under 2800 users on.

I have increased the network time out to 30 seconds on the webservers
and the box running the statesever process per
(http://support.microsoft.com/default.aspx?scid=kb;EN-US;308097) , but
still see the problem.