Occassionally some of my fonts will start missing characters or start not showing right(Ubuntu 14.10 w/ Gnome 3.14 but might effect others too). I guess the cause is corrupt font files.
Heres what you have to run to fix it. Dont worry the command is safe and I have run it more than a few times.
sudo apt-get install --reinstall --purge fontconfig fontconfig-config
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