Problem with gem1.8

[Stefan Palm <stefan.palm%pdmc.net@localhost>]

Hi folks.

I would like to install redmine on my box and tried to follow the installation 
guide (http://www.redmine.org/wiki/1/RedmineInstall).
But actually I'm failing on the first step as (pkgsrc) 'gem1.8' won't recognize 
"http://rubygems.org/"; as a valid repository.

% gem env 
RubyGems Environment:
  - RUBYGEMS VERSION: 1.3.7
  - RUBY VERSION: 1.8.7 (2010-08-16 patchlevel 302) [sparc-solaris2]
  - INSTALLATION DIRECTORY: /usr/pkg/lib/ruby/gems/1.8
  - RUBY EXECUTABLE: /usr/pkg/bin/ruby18
  - EXECUTABLE DIRECTORY: /usr/pkg/bin
  - RUBYGEMS PLATFORMS:
    - ruby
    - sparc-unknown
  - GEM PATHS:
     - /usr/pkg/lib/ruby/gems/1.8
     - /home/spalm0/.gem/ruby/1.8
  - GEM CONFIGURATION:
     - :update_sources => true
     - :verbose => true
     - :benchmark => false
     - :backtrace => false
     - :bulk_threshold => 1000
  - REMOTE SOURCES:
     - http://rubygems.org/

% gem install rails -v=2.3.5 --http-proxy=http://mmoproxy.<somedomain>:8080/
ERROR:  http://rubygems.org/ does not appear to be a repository
ERROR:  Could not find a valid gem 'rails' (= 2.3.5) in any repository

The same command with the same 'gem'-version (taken from Ubuntu) will work fine 
so I think this a pkgsrc issue.
Any ideas what the problem is?

TIA,
Stefan