Gradual memory consumption by Automatic Updates on XP2

Windows XP SP2 end-user workstations fully patched up to the beginning of
September, with 512MB of RAM

It was noticed the SVCHOST process with WSUS started consuming memory
steadily over the course of a few days until the machine become unresponsive
and a reboot is necessary, e.g. starting size 20mb approx and growing to
350mb even with all applications closed.

This SVCHOST hosts a large number of services, such as

Automatic Updates
Computer Browser
Cryptographic services
DHCP Client
Distrlibuted TLink Tracking Client
Error Reporting Service
Logical Disk Manager
Secondary Logon
Security Center
Server
Shell Hardware Detection
System Restore Service
Windows Audio
Windows Firewall
Windows Time
Wireless Zero Configuration
Workstation

This symptom is universal across all client systems that use a base suite of
apps - IE, office, msn etc.

Using Sysinternals process explorer doesn't provide any further information
-all of the threads within svchost.exe look legitiminate.

Using a documented method enabled me to configure a SVCHOST process to
contain the Automatic Updates service only, and was able to confirm that the
XP system *constantly* makes contact with the internal WSUS server and the
corresponding increase in memory consumption

It was suspected the posting in
http://www.wsus.info/forums/index.php?showtopic=8166 applies to my case

where (quoted from the above URL)

"....In-short, it seems if you include Office 2003 updates in your WSUS
synchronisation and you have workstations checking for relative updates to
this software, SVCHOST uses 100% CPU when the Automatic Updates client starts
running. I've no idea why this happens, but even if I run a manual Office
Update using the option in Outlook "Check for Updates", the same problem
occurs when the browser scans the PC, except it's not SVCHOST using the CPU,
it's the browser process instead!

I've found that the way to get around this issue in a WSUS environment is to
decline and remove all Office updates and exclude Office 2003 from the WSUS
Synchronisation...."

The difference being CPU rather memory consumption is experienced.

I am tempted to get around this issue in a WSUS environment by declining the
"Check for Updates" and removing all Office updates and excluding Office 2003
from the WSUS Synchronisation.

Thanks for any advice


Hong