Images displaying different sizes

I have an Image Show GK4 module on the home page here http://www.genderjustice.org.za. All images are 964x350 and the module set to the same size, but some images appear with black lines, others shorter... what is going on?

thanks
Ian

Please check your Image Show settings and especially function to create thumbnails, if it is enable IS will resize image to defined resolution and keep aspect ratio that's why you see this black stripes.

Thanks - I've turned off thumbnails and now it's working fine. I don't understand why this was happening, though - the images were all the same size so should have scaled correctly?

Thanks for the quick response, Ian

The images may be with the same size but this size is probably different than module size.