Bockq and beck, did you reboot the system after setting the ACL for shares? as some settings require reboot, and some of our customers do not reboot and continue working, the system work just fine with them tell reboot, why, because when a system ask for a reboot that means it need to do some changes for some system files, while keep working without a reboot, that configuration/changes remind in the memory, so after a late reboot, some system lose this settings.