I am using the "Product Image" for the thumbnail in my product listings, and whatever size image I put in, it ends up pixelated. Generally I have prepared all the images to be smaller than the specified dimensions. They are not changing in size, but simply appear pixelated.

Does anyone know what is causing this? And what I can do about it?

You can see examples here, http://www.spacefurniture.co.uk/OurProducts/ChairsStools/tabid/504/Default.aspx?categoryid=1

Thanks

Tony

They are all JPGs of GIFs and there isn't a problem with source.

I tested it by temporarily using one of the button GIFs as a product image and you can clearly see a difference in quality between the button as the product image and the button below the image.