Trouble with image size SKT Magazine theme

I am having trouble with the images on my pages. When inserting media to my page (using medium size and no alignement) the images shows up much larger and stretched on my page: http://pickyromancereaders.com/aliens-that-look-like-aliens/

I used to use a different theme, and there the images worked fine. Three would be next to each other on each line of the page, looking nice and clean. When I swapped over to SKT Magazine the images became large as you can see on the link, and the only way I can make them smaller is to align each image to the left. For some reason that makes the sizes correct, but it ends up looking strange and is hard to work with.

Does anyone know how to fix this, besides changing the theme?

I should also add, if I change the image size and update the page, instead of the size changing it stays the same size but crops and stretches more.