I don't use the drop-in widget as the behavior is so OS dependent. I have a unit with a "RunSaveDlg" routine that creates one in code, with IFDEFs for the OS, and warning dialogs. I can use it in all my projects without having to remember the idiosyncrasies of each OS.
Windows does pretty much as expected, Linux does not give an overwrite warning (as far as I can tell), and Mac does this weird dance that we have been talking about, sometimes causing an extra warning box.
It does sound odd. Linux seems secure enough, what extra does Apple need? I get annoyed with Apple, but still own a few Macs, and it is not an option for me to not support them.
It is all workable, thanks!