WP Theme changing the appearance of the Dashboard

Hi!

I installed the WP theme Hemingway. I liked it och tried to create a child theme, just as I’ve did with Twenty Twelve. Somehow I couldn’t do a child theme. After that a very strange thing happened. The WP editor looked totally different when I activated the original Hemingway theme. Link colors were different, columns totally out of proportions and so forth. Why is this happening?

I’ve tried uninstall and install again but with the same result. Is it a preference file or something like that who causes the problem? I would like to use the Hemingway theme but the WP editor looks totally weird when I use it.

Any ideas anyone!?

Best wishes!
/P