I took a look at your listings and see the problem. It looks like the original _o.jpg of the image is somehow corrupted, and that small placeholder image is being substituted. Why it's corrupted may be part of the problem Mike reported (unknown).
I would file a Support Case and let Auctiva investigate why the original image has a problem, but the 400x300 and thumb images (same upload) are OK (I looked at all three of them for one example). Here's one of the failing examples from your listing 230324770543.

I do have a suggestion you can try. Locate the image on your Image Management page at Auctiva, use the select checkoff box to the left of a problem image, and use the Replace button to upload a replacement image (same image). Hopefully, that will refresh the problem image. If that works, clicking on the replaced image on the Management page should show the full-size original image correctly, instead of that small blue image.
Danno