If this does not work as expected you could try something. Create a KoboRoot.tgz containing a KoboRoot.tar with nothing as the font inside in the respective path. Then copy the KoboRoot.tgz to the .kobo folder of the reader.
Edit: Thank you for pointing me to Malabar. I just installed it on my Touch. I like especially that it is a bit larger than the other fonts, so it is easier for me to read the dictionary pop-up texts.
Last edited by tshering; 01-16-2013 at 05:11 AM.