hi frozndevl! Windows is built that way ... as per
MS QUOTE
WFP uses the file signatures and catalog files that are generated by code signing to verify if protected system files are the correct Microsoft versions.
... you said you have already figured a way to do so but just in case yuo have not come accross this yet (this uses modified files), allow me to quote Fred Vorck:
QUOTE (fdv @ Apr 11 2006, 08:09 AM)

On a different subject... SFCFILES.DLL by the way works on ALL versions of Windows, just to clear that up. SFC.DLL and SFC_OS.DLL are different matters entirely. You can use SFCFILES.DLL and no other modified binaries and SFC will be disabled. To recap, for the confused
To shut Windows File Protection off:Use a modified SFC.DLL in Windows 2000
Use a modified SFC_OS.DLL in Windows XP and Windows 2003
No need for a modified SFCFILES.DLL
To disable Windows File Protection causing it to check an empty list:Use a modified SFCFILES.DLL in ANY version of Windows
No need for a modified SFC*.DLL
For complete overkill, so that Windows File Protection is shut off AND has an empty list which it doesn't even check:Use a modified SFC.DLL in Windows 2000
Use a modified SFC_OS.DLL in Windows XP and Windows 2003
AND Use a modified SFCFILES.DLL in ANY version of Windows
... this info was very helpful!

... to add, deleting .cat files is likewise doable via nLite ...