Are you both submitting listings through ebay or Auctiva?
I know when you first start-up with Auctiva, all your active ebay listings are essentially modified to add the Scrolling Gallery/SG (that's a one time). After that, I was under the impression you only got the SG automatically added with submissions from Auctiva.
headmuseum, I looked at your prior post and see you asked me directly. I'm sorry I missed that, but I'm an irregular poster to the Forum and don't work for Auctiva. I did look at that auction number 260225846529 you gave, and see it had no SG. But, I also noticed it had no Auctiva banners and looks like a standard ebay lister submission. You can export the code for the SG and add it to a listing you submit from ebay. However, I'd use Auctiva and take advantage of their free scheduler, picture hosting, and templates (to name just a few goodies).
Danno
Edit: You can add the SG to any active ebay listing by going to Store tab and look under the SG shown for "Scrolling Gallery HTML". That's the code you can copy and paste to ebay using ebay's Revise listing editor. Switch the Description section editor to HTML code and paste the code to whereever in the description section you want it placed. Use Preview to double-check placement and working before you save to complete the Revision, or you can back-off and try again.
Danno