Attempted to add a cow-worker to a MSN (Windows Live) Messenger Group today.


When sending from within messenger, the invite went from my screen but never arrived.
Tried again from the group website and it said I couldn't invite him:


"This person doesn't allow invitations"


Turned out that his account needed setting to a Limited Profile, rather and Private.
Changed that, and was then able to invite him to the group successfully.