When adding a script from InTrust Manager | Configuration | Advanced | Scripts you get an error when adding VBScripts (JScript and ECMAScripts work).
InTrust Manager tries to open this registry key: HKEY_CLASSES_ROOT\VBScript\CLSID and requires "Full control" permissions which are not granted by default.
Add the script using InTrust Manager installed on Windows 2003 and/or XP.
Set "Full control" permissions on HKEY_CLASSES_ROOT\VBScript\CLSID for the account under which InTrust Manager runs (you may need to change Owner of this key)
ST78952 logged for fix in future release.