Center Veritcal Images in Slideshow

I have a client who has a gallery with vertical and horizontal images. The images are not all the width of the gallery and they are ALL aligning to the left. I’ve search and tried various options but I can’t get the images to all center inside the slideshow.

Example: http://www.rosephotography.us/weddings/

The second image is a veritcal image to the height of the slideshow, but not the width.

Any suggestions?

http://wordpress.org/extend/plugins/nextgen-gallery/