Blank page or error

Hi. I try to install Rforum and have it running.

I set RAILS_GEM_VERSION = ‘1.2.3’ in environment.rb
But it may be useful for you to know that rails 2.0 is also installed on
my machine

With the version 0.2 found zipped at rubyforge, I get the following
error while typing:
rake migrate

rake aborted!
Regexp anchor characters are not allowed in routing requirements:
/^[0-9]+$/

The error is the same when typing
rake db:migrate

With the version from the darcs repository (
http://darcs.andreas-s.net/rforum ), I get no error, but
http://localhost:3000/ is a blank page (through server is running for
sure)
and
http://localhost:3000/user/register is also a blank page.

Any idea that may help me?