Problem with WMI in WinPE - null: Invalid Syntax Error

I have a test network set up with WDS installed on Windows 2003
server. PXE booting works fine, and I can map network drives without
a problem. The problem I'm having is with a custom VBS script. I
created the WinPE boot image per the instructions in the "Create a
Custom Windows PE Image" section of the WAIK help file. I did add the
WinPE-Scripting-Package, and cscript.exe is there and works. The
problem I have is with this line in any VBS script:

Set objWMIService = GetObject("winmgmts:\\.\root\cimv2")

I get this error: "(null): Invalid syntax" I actually put just that
single line into a vbs file by itself and tried to run it, and got the
same error.

This is particularly frustrating because it was working up until a
couple of days ago, but I have no idea what I may have changed to
break it. I've tried restarting the server and the client computer.
I've re-made the WinPE boot image several times. I'm stuck. What
could be causing the "null: Invalid syntax" error?

Thank you for your time!
Aaron