Option AGAIN ! images AGAIN!

Here the situation;

3 option combination - A B C (positions 0 1 2)

Problem I was investigating - When displaying the product listing in category the only images that show are images for option A. All others show “noimage” these don’t have A in stock they only have B & C. Asumption would be the listing would show the image for what is in stock based on the position value. A out of stock then it looks at B etc etc

And doing some testing, I set all options for the first product in the category. I gave it a image for each option to show I could confirm what was happing. Image for option A showed. Then I thought what if I deleted the out of stock options ? so if I had B but not A & C I delete options A & C from the product.

In my test product I deleted option A and took a look at the products list in the category. Great ! now the image for option B is showing for the test product. Disaster as ALL other products show “noimage” <— all the have option A but not option B instock.

So it seems the product listing in a category takes whatever option is “in stock” first and then only shows images for that option type. If you first product has only option C in stock then only images from those options will show for all products. Anyone any clues to how this can be fixed ?