Yes, this is a known issue that...
*twitch*akhfslkfhskjfhskjhfkwjhfehkwfiwufhBLARGH
Okay now that that is over.
Minion keeps its modules within the user directory, not within the app directory.
http://wowinterface.com/forums/showthread.php?t=24088
... will tell you where the user directory is.
To keep things simple, you either need to 1) copy that directory from one user to the other user, or 2) reinstall minion for every user into program files or 3) install minion into each user's home directory.
It isn't pretty, no.