I had a perfect wordpress site going on when installed on dotra.se/wordpress but then I figured I wanted it directly in the root folder and made a clean install there. Now I find that wordpress works, but only with the Default theme. When I try using my own theme it shows up, but with out any formatting, just text.
To get around the problem I tried to keep wordpress in the wordpress folder and followed the instructions from the wp-site on how to show it through only typing the root name in the browser. All I got then was a white screen.