Any luck I am also having this error
I was able to use the get_comment_author to make this work. In case anybody is curios here is the code.
html_entity_decode(get_comment_author(), ENT_COMPAT, 'UTF-8');
Will wp_specialchars_decode work? I have never used this function before?
I am having a similar issue also. I am using ubuntu PHP Version 5.2.3-1 ubuntu 6.3 running WordPress 2.7.1. It appears only in firefox 3, where it will display source code instead of the normal web page. Any luck or ideas?