Sorry, I get it now. This does seem to be a Personas issue, I agree. It works OK in WebGUI as well as SAPgui. If it doesn't work in Personas Basic View I don't think there will be a setting you can change in a flavour to make it work. Oddly, all of the buttons on the toolbar work apart from that group of four - append, insert, delete, duplicate. I wonder if there's some caching going on in the Personas client that is preventing those buttons from having an effect?
This is either a question for somebody from the Personas team, or else needs to be reported to OSS as a bug if that's what it turns out to be.
Sorry I can't be of more help,
Steve.