I notice that the default font for displaying repositories is a Courier-type font. I am using Firefox 3 on Ubuntu Hardy and find that this font does not display all that well; it looks squashed and unclear (as Freetype isn't that good at rendering small serif fonts, even with bytecode interpreting switched on). I recommend specifying a standard Linux sans-serif mono font in the CSS such as DejaVu or Vera Sans Mono first, then going to other fonts which will display if DejaVu or Vera is not available. BTW, the standard Hg web interface uses a sans font, as do Launchpad, GitHub and Gitorious.
Issue #264 resolved