Redmine

Hi,
I want to try out a recent release of redmine. I am running within Ubuntu 12.04.
I am following:
http://www.xunilarium.com/2012/05/how-to-install-redmine-201-on-ubuntu.html#!/2012/05/how-to-install-redmine-201-on-ubuntu.html

Redmine runs under webrick but I get the browser message:
The directory "/var/www/redmine/public" does not appear to be a valid Ruby on Rails application root.
when Apache2 is started
Nothing in /var/log/apache2/error.log
What do I need to do?