Alter product listing image size?

Hi there,

I've just upgraded to the latest version of hikashop, and one of the many things that it's thrown out of place is the the product listing image size. I'm using a "div image and title" layout for the product page. It now trys to display the image full size, but because the width of each product pane is set and the overflow is hidden, we only see the left 150px or so, and the heights of each pane vary hugely.

So here's what I've come up with:

Can't use CSS to alter it because the problem arises from the "width" and "height" properties in the actual <img> tag being set. If I fix the image width using css, the height therefore doesn't scale and I end up with a very deformed image. If I delete the "height" property specification and create a css rule to set the width to 150px all in firebug, everything works out great.
The <img> tag isn't actually specified in any Hikashop "view" file, as it's assembled elsewhere in the system and returned by a method to the view file.

So...
Is this a system setting that I'm not aware of?
If not... Where is the method that is returning the <img> tag so I can alter it to not specify any "height" value.

The link to the site under development... claycellar.org/index.php/books