InstantRails upgraded from 1.1.6 has problems:.rb:423:in `re

I developed a project on RoR 1.1.6 and it works fine.

On my development machine ( Windows XP, InstantRails 1.4)
I used gem install rails --source http://gems.rubyonrails.org
–include-dependencies
and upgraded Rails to 1.1.6.5848

When I tried to start my application, the following error occurs and I
couldn’t find any clue to solve it. Please help.

C:\RoR1.2\rails_apps\bidhelper_dev>ruby script/server webrick
=> Booting WEBrick…
C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1.5848/lib/active_suppor
t/dependencies.rb:423:in remove_const': cannot remove Object::ModelTranslation (NameError) from C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1.5848/lib/ active_support/dependencies.rb:423:in send’
from
C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1.5848/lib/
active_support/dependencies.rb:423:in remove_constant' from C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1.5848/lib/ active_support/dependencies.rb:369:in new_constants_in’
from
C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1.5848/lib/
active_support/dependencies.rb:369:in each' from C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1.5848/lib/ active_support/dependencies.rb:369:in new_constants_in’
from
C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1.5848/lib/
active_support/dependencies.rb:496:in require' from C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/rails-1.1.6.5848/lib/commands /servers/webrick.rb:52 from C:/RoR1.2/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27 :in gem_original_require’
… 7 levels…
from
C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1.5848/lib/
active_support/dependencies.rb:496:in require' from C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1.5848/lib/ active_support/dependencies.rb:343:in new_constants_in’
from
C:/RoR1.2/ruby/lib/ruby/gems/1.8/gems/activesupport-1.3.1.5848/lib/
active_support/dependencies.rb:496:in `require’
from script/server:3