Redmine

hi,

I just upgraded my version of redmine from 1.1.x to 1.2.1.
1.2.x need a new version of rails (2.3.11) and rack (1.1.0). I installed them, but kept rails(2.3.5) and rack(1.0.1) as they are needed by mongrel_cluster I think ?

The problem is that now, when I start up-to-date redmine with webrick => no problem
with mongrel_cluster (I copied my old mongrel config etc) => it's failling with this in mongrel_cluster logs :

** Daemonized, any open files are closed.  Look at /home/mongrel/pids/mongrel.8001.pid and /var/log/mongrel.8001.log for info.
** Starting Mongrel listening at 0.0.0.0:8001
** Initiating groups for "mongrel":"nginx".
** Changing group to "nginx".
** Changing user to "mongrel".
** Starting Rails with production environment...
/var/www/redmine/config/../vendor/rails/railties/lib/initializer.rb:271:in `require_frameworks': no such file to load -- rack (RuntimeError)
        from /var/www/redmine/config/../vendor/rails/railties/lib/initializer.rb:134:in `process'
        from /var/www/redmine/config/../vendor/rails/railties/lib/initializer.rb:113:in `send'
        from /var/www/redmine/config/../vendor/rails/railties/lib/initializer.rb:113:in `run'
        from /var/www/redmine/config/environment.rb:20
        from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
        from /usr/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/rails.rb:147:in `rails'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:113:in `cloaker_'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/configurator.rb:149:in `call'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/configurator.rb:149:in `listener'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:99:in `cloaker_'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/configurator.rb:50:in `call'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/configurator.rb:50:in `initialize'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:84:in `new'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:84:in `run'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/../lib/mongrel/command.rb:212:in `run'
        from /usr/lib/ruby/gems/1.8/gems/mongrel-1.1.5/bin/mongrel_rails:281
        from /usr/bin/mongrel_rails:19:in `load'
        from /usr/bin/mongrel_rails:19

I realy don't understand this error, as it seams to be unable to load rack, which is in my gem list :

*** LOCAL GEMS ***

abstract (1.0.0)
actionmailer (3.0.3, 2.3.11, 2.3.5)
actionpack (3.0.3, 2.3.11, 2.3.5)
activemodel (3.0.3)
activerecord (3.0.3, 2.3.11, 2.3.5)
activeresource (3.0.3, 2.3.11, 2.3.5)
activesupport (3.0.3, 2.3.11, 2.3.5)
arel (2.0.6)
builder (2.1.2)
bundler (1.0.7)
cgi_multipart_eof_fix (2.5.0)
daemons (1.1.0)
erubis (2.6.6)
fastthread (1.0.7)
gem_plugin (0.2.3)
i18n (0.4.2)
mail (2.2.12)
mime-types (1.16)
mongrel (1.1.5)
mongrel_cluster (1.0.5)
mysql (2.8.1)
polyglot (0.3.1)
postgres-pr (0.6.3)
rack (1.1.1, 1.1.0, 1.0.1)
rack-mount (0.6.13)
rack-test (0.5.6)
rails (2.3.11, 2.3.5)
rake (0.8.7)
rmagick (2.13.1)
thor (0.14.6)
treetop (1.4.9)
tzinfo (0.3.23)

I checked gem environment etc, everything looks ok, and it was already working before the redmine update.
That's where I'm stuck, anyone have an idea ?