I looked at a few of your Listings. Are you manually inserting (Insert an Auctiva Hosted Image button) and stacking those pics at the bottom of your typical listings as I'm seeing a single picture above the Title which I suspect is using template method, and then a group/stacked array (one above next) on lower portion of description which I assume are manually inserted? If so, are you using the picture alignment for those lower images with Image Properites or using the Center Justified just above the word Font on the coding bars?
To use Center Justified (which I've use for that exact purpose on past listings), select all the images you want centered so they show a dark over-shadow using the mouse and cursor method, and then apply that Center Justified.
See if that works as a test.
If not, can you describe the method (step-by-step) you're using to insert the images.
I think I'm seeing align=middle for the problem code on sample listing I checked, and my method uses align=center (verified checking HTML by test on the lister). I think middle is used as a wrap-text method and does appear as a property attribute on pic, but I'm a little rusty on my coding.
Danno