Uninitialized constant WEBrick

I have just upgraded installed rails 1.1 using gem. I have set up a
rails app using radrails. I have set up one model for testing and set
up one migration in order to create the table for that model. When I
type rake migrate I get the following error message.

rake aborted!
uninitialized constant WEBrick

(See full trace by running task with --trace)

I have attached the trace below.

This happens both on windows and Centos 4.2. I am using mysql 4.x.
Anybody have a clue?

** Invoke migrate (first_time)
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
rake aborted!
uninitialized constant WEBrick
/usr/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:123:in
const_missing' /usr/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:131:inconst_missing’
/root/borg/test_callflow/config/…/config/environment.rb:56
/usr/lib/site_ruby/1.8/rubygems/custom_require.rb:21:in require' /usr/lib/ruby/gems/1.8/gems/activesupport-1.3.1/lib/active_support/dependencies.rb:147:inrequire’
/usr/lib/ruby/gems/1.8/gems/rails-1.1.2/lib/tasks/misc.rake:3
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:387:in execute' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:387:inexecute’
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:357:in invoke' /usr/lib/ruby/1.8/thread.rb:135:insynchronize’
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:350:in invoke' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:364:ininvoke_prerequisites’
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:999:in each' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:363:ininvoke_prerequisites’
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:356:in invoke' /usr/lib/ruby/1.8/thread.rb:135:insynchronize’
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:350:in invoke' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:364:ininvoke_prerequisites’
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:999:in each' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:363:ininvoke_prerequisites’
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:356:in invoke' /usr/lib/ruby/1.8/thread.rb:135:insynchronize’
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:350:in invoke' /usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:1906:inrun’
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/lib/rake.rb:1906:in `run’
/usr/lib/ruby/gems/1.8/gems/rake-0.7.1/bin/rake:7
/usr/bin/rake:18