Undefined method `alias_method_chain' for ActiveRecord::Vali

Hi,

I had a problem with a dependency so I decided to upgrade from rails v.
1.1.6 to rails v. 1.2.3.

The problem persits and I don’t know if it’s a dependency issue or
another thing…

here’s all the information I got…

The webpage is showing:
Application error
Rails application failed to start properly

And if i execute:
ruby ./dispatch.fcgi

If I try to boot webbrick i get this:
http://pastie.caboo.se/73579
almost same error if I execute ./dispatch.fcgi:
http://pastie.caboo.se/73580

My gem list can be found here
http://pastie.caboo.se/73566

My enviroment.rb is telling this:
RAILS_GEM_VERSION = '1.2.3

And i have rails freezed to that version…

I’ve tried to downgrade and upgrade everything… but I don’t know if
I’m going in the right direction… any idea?