[Users] persistent modifications to /etc/hosts?

Hello, I would like to add an entry to /etc/hosts. I modifiy it and then: # persist /etc/hosts File already persisted: /etc/hosts But actually at reboot my modification is not there again.... This with ovirt-node-iso-2.5.5-0.1.fc17.iso # cat /etc/redhat-release oVirt Node Hypervisor release 2.5.5 (0.1.fc17) What am I missing? Thanks in advance, Gianluca