The only thing I can think of is an old trick to limit concurrent connections. Sounds kludgy but hey... it's early in the morning and I'm still on my first cup of coffee.
It is done by limiting the number of users to the share to 1. If you then try to map to the share and it fails then there must be 1 already mapped.
_________________________
Give a man a fish and he will be back for more. Slap him with a fish and he will go away forever.
