[tor-relays] Problems with nameservers and permissions

I've just started running a relay on Linux with Tor starting automatically, however arm reported that "all nameservers have failed" and, unsure what to do, I stopped Tor to go look up the problem. Then when I tried to start it in Terminal again I'm greeted with this:

Jun 18 11:53:15.000 [warn] Couldn't open "/home/george/.tor/lock" for locking: Permission denied Jun 18 11:53:15.000 [err] set_options(): Bug: Acting on config options left us in a broken state. Dying.

I've tried changing the permissions of the directory and the lock file but it still says permission denied. What should I do?

I'm running Tor 0.2.3.17-beta-1 on Ubuntu 12.04.

Thank you for any help, George