Difference in performance between Windows Server 2003 SP1 and SP2 when IIS site set to "Enable

Hi

We have a 4 tier setup with a client (Internet Explorer (IE)) that
accesses a SharePoint server, that accesses some web services, that
again access a database.

THe setup is on three machines, with IE on machine 1, SharePoint
server on machine 2, and the web service and database on machine 3.

For this to work, we have to set the "Directory Security" of the web
service site on the IIS to "Enable Anonymous Access" using a test user
account's credentials ( and we have to uncheck the "Integrated Windows
Authentication"). Not that I know much about security issues, but as i
understand it, the web service uses Kerberos authentication, and this
can be bypassed using the above settings.

The funny thing now is that this setting works significantly faster on
a Windows Server 2003 SP1 than on Windows Server 2003 SP2. Does anyone
know why that can be the case.

I know that if we run IE on machine 2 (the same machine as Share point
server), then we can set the "Directory Security" to "Integrated
Windows Authentication", and it will work as fast on both systems.
So something has changed on SP2 that makes this authentication slow,
or something.


Does anyone have any idea why this is the case?

I would really appreciate any help with this, since we have to
understand if there is a significant difference between SP1 and SP2,
and if we are doing something wrong.

Thanks
Jeeji