vi editor throught the system controller

Can someone explain to me why the vi editor acts very erractic when you access it through the xscf on a M3000 ;after you console over to the domain. The system was in single user mode. It seem as though it become really unstable in this situation. I was trying to edit /etc/host file. I had disconnected the system from the network. I thought I made the changes when I cat the file but after I init 0 and the I booted to single user mode some of the changes were not made. Thanks