Moini, is that "stop id" related to the swatch? I seem to recall that swatches are id'd as gradients (even though they aren't gradients), but I don't know how the stop id fits.
Yeah, that's what it looks like. I just created a swatch in a new document, and it has the same stop id.
But wait, regular gradients have the same thing. Does that mean that images with gradients can't be saved to PDF? That would be a pretty serious bug, wouldn't it?
Well, I successfully saved an SVG file as PDF, with both a swatch-filled and gradient-filled object. Let me test gauche's.... Hhmm, no luck there.
There must be more to it, than just the stop tag in the XML. Can you explain more, Moini?