Can't connect anymore after changing root user

[eraserhead]

I installed subsonic on my ubuntu 14.04.1 LTS server

I get warnings that using root user is not secured so i went to /etc/default/subsonic and changed to user to another existing user.

When restarting the service and connecting again i get 'unable to connect' in my browser.

It stays like that even after i change it back to root and restart, after about 5 mins it works again. (what's that?)

So what's the correct procedure to change the user?

edit: i changed the user to www-data and it seems to work now. I hope this is secure.