Yumex 1) complains that it can't download stuff and bombs out. Even if yum proxy has been set and yum is working.
To fix, edit /etc/yumex.conf and add the proxy in:
proxy = "http://your.cache.address:port"
The quotes are required!
Some information about the grub font error at http://unsolicitedbutoffered.blogspot.co.uk/2012/06/fedora-17-lxde-review-just-facts-mam.html