[Theme: Portfolio Press] Issues with thumbnail sizes

Hi there, I just found this theme, it’s perfect for what I need it for, and I’m very excited to set it up. However, the thumbnails are only crunching by width… they’re all different heights and it does not look grid like at all 🙁 I’m confused because the first item thumbnail looks like it cropped the height perfectly, but all the ones after it didn’t.

I went to the developer’s main page, who is awesome about providing support for his themes, but the solution he gave to this problem involved editing a .php extension I don’t seem to have. I didn’t get portfolio-post-type.php with my download or it’s not with the rest of my extensions, so I’m not really sure what to do.

Any idea what I’m doing wrong?

http://wordpress.org/extend/themes/portfolio-press/