Thumbnail Resizing on Featured Categories

I am currently setting up a blog using the “news-magazine-640” theme. I LOVE the layout and how the homepage dynamically updates as you add new posts to categories.

The first problem I had was that the thumbnails were not showing up, and thanks to neononcon on a previous thread, I was able to fix this problem by adding add_theme_support('post-thumbnails'); to “functions.php” then making sure each category box was retrieving the correct photo.

Now I have thumbnails on my homepage, and each thumbnail is shown on the homepage, but depending on where the thumbnail is in each “Featured Category” box, the Theme shifts and molds the image. Because each Category box changes with a new post (thus each thumbnail changes its position in the box), the photo shifts and molds again to fill the new position. A thumbnail will look great in one position, but horrible in another.

To solve this problem, I think I would just like to set every thumbnail position in the “Featured Categories” boxes to the same size (or maybe set the theme to crop the thumbnail instead of resize it?). I’m new to PHP, so this seems a bit confusing to me. How would I go about doing this kind of an edit?

And here is a picture of the problem that I’m having, I thought some visual reference would help: http://twitpic.com/2832cd