This is a return to a post from July '04 where earlier versions were noted as not returning a value on @LOGONMODE. I've experimented with this again and it also exists in 4.23 (at least it does in my environment!).
Just in case anyone was wondering why you'd use it, it's really useful for debugging where you want to ensure you can test production changes against the latest release area i.e. if LOGONMODE isn't '1' we're debugging and therefore pull the sub-scripts and settings from the over there (rather than one of 60+ domain controllers).
Am I unique in seeing this, or is it an accepted fault?