Hi Jules,
I think you should add a few entries to the default font names for Juce, the current list is:
“Verdana”, “Bitstream Vera Sans”, “Luxi Sans”, “Sans”
I have an ubuntu distro were the none of those default fonts is found and an monospace font ends up being selection, which is quite ugly. So I suggest to add “Liberation Sans” and “DejaVu Sans” to the list of sans serif fonts, “DejaVu Serif”, “Liberation Serif” for serif fonts, and “DejaVu Mono”, “Liberation Mono”