668 System command cannot be executed - 1: Not owner

Good Day I have the following problem which I would appreciate some help with I have a Stored Procedure which executes a System command to call a 4GE program. When executing the stored procedure directly on the server using DBACCESS, everything works correctly. I have written a Java application which calls the Stored Procedure using JDBC The application works on some computers, but not on the others. The error that it gets is "668 System command cannot be executed" and ISAM erroris "1 Not Owner". Both computers are using the same login credentials, and the same version of the JDBC drivers. The executable 4GE has execute permissions for all users. I also have similar results trying to execute the Stored Procedure with other JDBC clients eg. SQuirreL SQL. It works on some computers but not others. Please can somebody point me in the right direction. Thanks Gavin Rifkind