seems a bug in rails 1.2.2 / activerecord / sqlserveradapter

Hi all, please look to my example code:

the model:
  class ProductCategory < ActiveRecord::Base
    validates_uniqueness_of :name
    validates_presence_of :name

and run this:
  category =
  puts nil.class
  puts category.valid?

it will return:

and I'm using sqlserveradapter in database.yml:

    database: xxx
    adapter: sqlserver
    host: .
    username: xxx
    password: xxx

I checked this page
and rolled back this change,
and this problem has solved for me.

did anyone got the same problem?