I thought this would be valuable to some of you that are new to Ubuntu. Being rather new to this Ubuntu Linux thing myself, I have struggled to get the terminal commands for fixing the .dmrc permissions issue just right.
Every SSH server uses a random key to identify itself. When SSH is installed a new key is generated. SSH clients keep track of the host key, if it changes the user can be warned that they might not be connecting to the computer they think they are. Most of the time this happens when the SSH server or the OS are reinstalled.