Oh there's more.

http://support.microsoft.com/?id=825751
says:
> /P user:GUI Replace security permissions similar to standard
> choices.

cscript xcacls.vbs c:\ /e /p users:gui
says:
Error: Permission Code not recognized: G
Error: Permission Code not recognized: U
Error: Permission Code not recognized: I

Maybe the author of the program and the author of the Knowledge Base article
should have a meeting?