NW 6.5 sp6

I am finding some users' home directory quotas are not accurate. C1 is reporting 0k in use... yet their folders contain anywhere from 20mb and up. I have reviewed some of the respective NDS user account attribs and found nothing out of the ordinary.
I stumbled across this after moving some user accounts via C1. user1.staff.locale1.org1.IMATREE moved to user1.staff.locale2.org2.IMATREE. Home folder contents were moved via windows explorer... logged in as a NDS admin user. Folder permissions were verified after the move, as were the NDS attributes of said user (preferred server, home directory volume and path)

Any insight as to a fix and prevention of future occurrence is appreciated.