I'm really interested in learning more about how use use FreeMind. I've been using a collection of text documents as "cheatsheets" that I can refer to, but it's less than perfect.
Do you have other java based software installed? Does that look ok?
http://packages.ubuntu.com/quantal/freemind
Ubuntu repos show freemind depending on openjdk (or Oracle) and that has a font package shown as a dependency.