Can No Longer Read Uninstall Keys with vbscript package run by SCCM

Hi, 

I've been using vbscript packages in SCCM for over a decade, and one thing I do is use the registry to determine if I need to uninstall an old program with the Value:

HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\
or
HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Uninstall

Example code snip:

UnstKey = "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{81BE0B17-563B-45D4-B198-5721E6C665CD}"
UnstVal = wshShell.RegRead(UnstKey & "\UninstallString")

If I run this manually, it works great, but all of a sudden, when I run a vbscript like this in SCCM it now returns: 
Invalid root in registry key "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{...}\UninstallString"

I normally run everything whether or not a user is logged on as System, but I did a test, and it even fails if I run the package as the user, which really surprised me. I check permissions in registry key, and Everyone has read, System has Modify.

This code was working about a month ago. No changes to SCCM that I know. Sadly, we are still running 2007 SP2

Please help!