Image size in Visual Portoflio

Hello,

I really like Visual Portfolio plug-in for WP but there is a bug which is very annoying. When I make a slider I add bunch of photos (vertical and horizontal) however for some reasons the vertical photos are okay but the horizontal photos are half size (as you can see in the example). My question is how can I make all photos to be the exact height without cropping images?

The page I need help with: [log in to see the link]