Having column named 'transaction' in a model leads to weird behavior

While the doc warns not to use associations that are named the same as methods in AcitiveRecord::Base, I could not find any warning about column names. But using a column named 'transaction' leads to strange behavior.

Create a model with a column named 'transaction', e.g.

class CreateItems < ActiveRecord::Migration
  def self.up
    create_table :items do |t|
      t.string :transaction

      t.timestamps
    end
  end
end

class Item < ActiveRecord::Base
end

Create instances of the class in console:

$ script/console
Loading development environment (Rails 2.1.1)
>> Item.create!
=> #<Item id: 1, transaction: nil, created_at: "2008-09-08 01:30:14", updated_at: "2008-09-08 01:30:14">
>> Item.create!
=> #<Item id: nil, transaction: nil, created_at: nil, updated_at: nil>
>>

Note the second (and all subsequent) attempt to create and persist an instance creates the instance but does not save it to the database.

If the column is renamed to something else, this problem does not happen.