Strange problem with IE

[Parag Godkar]

Hi There,

I have implemented the IMP webmail solution for my organisation. I have
implemented it on the following machine running the following OS - 

Red Hat Linux release 7.0 ( Guinness )
Kernel 2.2.16-22 on an i686
Single Pentium-III 800MHz , 256KB Cache , 256MB RAM

I have installed the following rpms for rh7 as per the instructions given
in horde-latest.Readme found on the download site
ftp.horde.org/pub/imp/rpms/noarch. 
       
All the rpms were taken from the Horde download site.

apache-1.3.14-3B
freetype-1.3.1-7
mod_php-4.0.3pl1-1
php-4.0.3pl1-1
php-imap-4.0.3pl1-1

mysqlclient9-3.23.22-3
php-mysql-4.0.3pl1-1

imap-2000-3
krb5-libs-1.2.1-8
openssl-0.9.5a-14
mysql-3.23.32-1.7
mysql-server-3.23.32-1.7

horde-1.2.4-1rh7
horde-mysql-1.2.4-1rh7
imp-2.2.4-1rh7

I have also implemented SSL so that people can access IMP through both
secure as well as non-secure means.

Everything is running perfectly fine. Thanks to the horde group for
creating such a fine Webmail Solution.

Now for the problem -
As people began to access their mails through IMP, the load on our
server increased and it began to slow down. So I enabled the auto timeout
feature in IMP - ( in /var/www/horde-phplib -- local.inc -- class
HordeSession ) as follows -

 var $lifetime       = 5;         // 0 = do session cookies, else minutes

This used to logout people automatically after an idle time of 5 minutes.
So, everything worked fine and the load on our server also decreased.

But, some client machines running Interner Explorer encountered strange
problem - People are able to login to IMP, see their mails but on clicking
the mail, IMP throws them out to the login screen. This is true for any
person logging ( Windows Login ) into those machines and then logging into
IMP. The machines have the following configurations -

2  machines   -   win2k professional  - IE5
1  machine    -   win2k professional  - latest updated IE5.5
1  machine    -   win98               - latest updated IE5.5

I observed that the problem vanishes the moment I disable the auto logout
feature.

Also, rest of the people running machines with similar configurations have
no problem.

Can someone please help!

Regards,
Parag Godkar.