MsgrObject CreateUser Security

Hello,
I'm running the script below.
It works fine in VB and in Word. However it's failing when running on WSH
(cscript test.vbs) with the error
C:\Development\IM_SIP\test1.vbs(10, 5) Microsoft VBScript runtime error:
Object required: 'msgr.CreateUser(...)'

There is no documentation about special security on WSH for this function.
Any ideas?

Thanks


Sub test()
Dim msgr
Dim pUser
Dim users
Dim service
Set msgr = CreateObject("Messenger.MsgrObject")
'MsgBox msgr.Services.Count
Set users = msgr.List(0)
Set service = msgr.Services.PrimaryService
Set pUser = msgr.CreateUser("user@ourcompany.com", service)
Call msgr.List(0).Add(pUser)
End Sub