Ok, so you have installed a version of eeeXubuntu, but there is a newer version available, but you don't want to format and start over from the beginning? Then this page is for you!
No known fix.
Fix by threedaymonk.
In a terminal:
tar zxvf eeexubuntu-update-r2-r3.tar.gz
sudo -u root ./install.sh
Use it at your own risk! There are no backups or checks! It worked for me against a couple of installations (one real, one virtual).