Image Zoom 'not' Working On Product Variations


I've noticed on my cs cart mv edition that the image zoom, (where you hover your mouse atop a product image and you get the zoomed version in a separate window to the side), does not work for product variations.

What I've noticed is that I can have multiple images of one product with no variations and the image zoom will work for all of those images without a problem.

If I then add variations to a product say - a different colour and different sizes - the image zoom will only work on the original product variations and will not work for any others including after you've selected a variation that does not have a different photo for eg. a different size only.

Does anyone have any ideas as to how to rectify this?