Here is what I found in d:\winnt\setupapi.log when I tried to install it
today:

[2004/12/05 05:20:01 1376.12]
Munged cmdline: D:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\IXP000.TMP\OEUPDATE.EXE
/q Q823353
EXE name: D:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\IXP000.TMP\OEUPDATE.EXE
Copying file D:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\IXP000.TMP\MSOERES.DLL to
D:\WINNT\system32\dllcache\MSOERES.DLL.
No signature was present in the subject.
Install failed, attempting to restore original files.
Restoring File: "D:\WINNT\system32\MSIDENT.DLL" from
"D:\WINNT\Temp\OLD333.tmp".
Restore attempt failed (will delay restore) error: Error 32: The process
cannot access the file because it is being used by another process.
Restoring File: "D:\WINNT\system32\MSOEACCT.DLL" from
"D:\WINNT\Temp\OLD331.tmp".
Restore attempt failed (will delay restore) error: Error 32: The process
cannot access the file because it is being used by another process.
Restoring File: "D:\WINNT\system32\INETCOMM.DLL" from
"D:\WINNT\Temp\OLD32F.tmp".
Restore attempt failed (will delay restore) error: Error 32: The process
cannot access the file because it is being used by another process.
Restoring File: "D:\WINNT\system32\MSOERT2.DLL" from
"D:\WINNT\Temp\OLD32D.tmp".
Restore attempt failed (will delay restore) error: Error 32: The process
cannot access the file because it is being used by another process.
Restoring File: "D:\WINNT\system32\INETRES.DLL" from
"D:\WINNT\Temp\OLD32B.tmp".
Restore attempt failed (will delay restore) error: Error 32: The process
cannot access the file because it is being used by another process.
[2004/12/05 05:19:55 1376.3]
Error parsing install section DefaultInstall of
D:\DOCUME~1\ADMINI~1\LOCALS~1\Temp\IXP000.TMP\Q823353.inf: Error 0x800b0100:
No signature was present in the subject.