followed the directions to install the stopdesign theme. it's available in my admin|options menu but when i click it the page refreshes and DEFAULT TEMPLATE is still selected. I cannot chose any theme actually. theme selection worked before installing the stopdesign theme though.
There's a possibility that the permissions on the theme.txt file aren't allowing writing... you might try 777ing it if you still want to use that feature.
Also, if you need to do it manually, it's the folder name of the theme (in the themes/ folder) you should put in there.