FCS is only deleting my FCP project file and not linked assets. please help.

When deleting a FCP project from FCS it does not give me the option to delete all linked media. It only deletes the FCP project file leaving me to delete all related media manually. In the user guide it says it should give me the option to delete the project and all files automatically but this doesn't happen on our system. Does anyone know why? and how to turn this function on?