I'm not trying to do this in OS X, it's in OS8.6. On Sheepshaver actually. What I do is load the toast image in Sheepshaver (as a hard disk in read/write mode). Then once the changes are made, I shut down Sheepshaver, make the file read-only and try booting from it. I've tried deleting the OpenFolderListDF file, and then either restarting or shutting down while the window is still open. But while the window will open if I boot from the hard disk, it won't if I boot from the CD. If I leave the window open and then eject the CD, it loses the Desktop and Trash folders and is rendered unbootable.