I've tried for hours to fit my header image correctly. But no matter what, they end up *really* big and stretched out. I've tried using the same height/length as the 3 original headers, even copying over the files.

You can take a look
http://manda-chan.animeblogger.net/

Ok, i just tried using print screen on my site, and replacing that header image size with one of mine and that seemed to work! I just figured out the header images do not fit all the way on the page themselves and they get cut out.

Have you looked at your header settings as follows:

ATO > Header Image look at Header Image: Height - make sure it is the same height as your header image.

ATO > Style and Configure Layout - I usually make the layout a fixed width - the same width as the header image. For example, if my header image is 1000px then I would make the Layout WIDTH and type (FLUID or FIXED) 1000px.

If this does not work, can you let me know the version of both wordpress and Atahualpa you are using.

Closing since the original post is over a year old