iis hostname & ip issues

Hi everyone
let me start by defining the setup
5 Servers (2 Win 2000, 2 Win XP, 1 Win 2003)
the code two simple asp pages

1. main.asp - Contains a simple db connection
   if there is a valid record in the db
   it sets the session variables
   
   Code:

   Session("usr") = Trim(Rs("login_name"))

   
   and redirects to home.asp
   else
   prints out Invalid Login in main.asp
2. home.asp - Contains the code for redirecting to main.asp if the session timesout else just print any valid message
   
   Code:

   If Session ("usr" ) = "" Then
   	Response.Redirect "main.asp"
   	Response.End 
   End If

Problem Statement -
if i use the ip address to connect to these servers
http://10.18.1.27/main.asp
there is no issues it diplays content in home.asp

but if i use host name like
http://qd_pal/main.asp
the session resets for only the (Win 2000 & Win 2003 Servers)
but for the XP machines it works fine the session is not reset

to make matters worse for browsers ie5.0 & 6.0 we face this issue
but if the bowser is netscape, mozilla and even ie5.5 (must be some security access?) it works fine

I dont know how many have faced an issue like this
Please help thanks in advance
reg
Vinoj

My guess is your IIS web structure is different on the different servers. How are you determining you session is reset? Perhaps there is something else that's causing your code to fail.

The web structure is the same
and the session timeout is set in global.asa

The same code copy is used over the different servers
In that condition it shouldnt run on the XP Machines
and also the Netscape and Mozilla bowsers show no issues
regards
Vinoj