DSM 6.1-15047 Update 1
There's bug/defect in task scheduler in that a user-defined script scheduled to run as a non-root user is executed in an environment where $USER is root, $HOME is /root, and the starting directory is /root, which shouldn't be readable by non-root users. This leads to permission errors when executing standard utilities like find(1).
Expected behavior: $USER is set to the user the script is scheduled to run as; $HOME and the starting directory are set to the home directory of $USER.