Try to run the file system repair utility from the Extended Tools section from Console, this will restart the system then try to remove the Apple temp files in the Extended Tools as well. If there are no errors from the Repair filesystem then check RAID health. Also remove the AFP from the share and from the NAS Settings, not sure if you just did the Settings or from the Share as that was not noted but try this after performing the steps mentioned from the Extended Tools (enter from the console screen CTRL + ALT + X to access the Extended tools ).