Commerce Server 2002 Service Pack 4 has been released. You can see some details here...
http://blogs.msdn.com/nihitk/archive/2006/10/11/commerce-server-2002-service-pack-4-released.aspx
Below is the list of bugs that have been fixed. This is the reason I hate commerce server. almost 5 years after its release, they are still releasing patches for memory issues and other bugs which I consider to be pretty major. This is a platform that is supposed to be able to run high volume commerce sites. I think the people who worked on the original code should be embarrassed of the work they produced.
http://support.microsoft.com/kb/924899/
Eric Hexter