[tor-relays] problem with tor-arm

Hello! I use tor-arm to manage my relay, at startup the following messages appear: [ARM_NOTICE] Unable to prepopulate bandwidth information (insufficient uptime) [ARM_NOTICE] Unable to save configuration descriptions (permission denied: '/home/username/.arm') Problem is the same for every user who runs arm (root, debian-tor) Already tried 777 this folder, and make "debian-tor" the owner - without success. Purge & reinstall does not change anything. I am running Ubuntu Server 12.04 x64. Whats wrong? best regards manu