Image Alignment Problems

I’m using WP 3.5.1 and Pinboard 1.0.7 as a theme. This is a gorgeously simple slideshow plugin and I want to use it desperately, but I’m having a few problems getting it to display images correctly.

1. My first and most glaring issue is that of mixing landscape and portrait images. When I attempt this, the landscape photos always end up aligned to the left. Is there a way to denote alignment for images in the gallery?

2. I also wanted to know where to define the size of the photos. It seems all over the place, depending on the first image in the set. Can I force every photo to display in 100% of the slideshow space (either width or height depending on whether the image is landscape or portrait), regardless of its actual dimensions?

Any help would be eternally appreciated! Thank you.

http://ww.wp.xz.cn/extend/plugins/simple-slideshow/