Am Not. I thought Model.save_thumbnail was just to save a thumbnail to it's own jpg file. I'm talking about the one you see in the preview box when you do a File | Open, or if you turn on thumbnails in an explorer window.
I think I may have found what I was looking for. There's an option under "Model Info | File" called "Redefine thumbnail on save". From what I can tell, the thumbnail only gets generated when you close the file, not when you save without closing, unless this option is turned on. I assume this is to improve performance on autosave, etc. Anyway, if I enable this option (manually), I get the behavior I want. Not sure if that option is available from within ruby. CB.