I upgraded my SMS 2003 Server to SP2 today. The upgrade completed normally, but after checking SMS Site Status, I noticed that the MP upgrade was failing wit these errors in the mpsetup.log file:
<07-16-2006 22:32:36> [22:32:36] @@ERR:25006
<07-16-2006 22:32:36> Setup was unable to create the Internet virtual directory CCM_System
The error code is 80020009
<07-16-2006 22:34:16> MP.MSI exited with return code: 1603
<07-16-2006 22:34:16> Backing up MPMSI.log to F:\SMS\logs\MPMSI.log.LastError
<07-16-2006 22:34:16> Fatal MSI Error – MP.MSI could not be installed.
Searched around and found a recent hotfix for IIS that corrects this problem. Article 913441 covers a problem with IiS 6.0 that causes the upgrade of the MP to fail. Called MS and after installing, the MP install completed normally.