Novell Delete Inhibit

I set the DI (Delete Inhibit) attribute on for a folder – therefore I can’t delete folder – yet files inside folder are getting deleted if they are not DI also – but not all the time – sometimes the files that are deletable do not get deleted – is this a bug ? – in any case I’d rather not flag each file in the folder as DI – and at same time make it so if user tries to delete entire directory or folder – it won;t leave me with an empty folder – the folder remains but the files inside don’t.