Nhttp does not release memory

Hi all.Sorry for my english…

My Domino server 6.5.4 on Windows 2000 Advanced Server SP4 has a problem with allocated memory for http task.

When the server start up, the amount of memory allocated by nhttp.exe task in Task Manager begin to increase until it causes the application accessed via browser not responding.

Then, I send to the console the command TELL HTTP RESTART and the console shows many messages like these:

17/01/2006 11:38:54 HTTP Server: Waiting for session to finish: Session State [Processing Request] Session ID [904] GET /sipr0/w_sipr_main.nsf/0/38A6031EDD68D306C12570F4004A7EF0?EditDocument HTTP/1.1

17/01/2006 11:38:54 HTTP Server: Waiting for session to finish: Session State [Processing Request] Session ID [905] POST /webintra.nsf/W_WelcomePage?OpenForm&Seq=1 HTTP/1.1

It seems that the server does not release the memory allocated.

This server is in SSO with another server; the Idle Session Timeout is 60 minutes, the Session Timeout is 480 minutes.

I tried to search in the forum, but I found many questions and no definitive answers.

Can U help me?

Tnx