Rails 2.1.2 => 2.3.2 columns as private methods error?

Something change in Rails 2.3.2 since 2.1.2, and I'm not sure what, or how to handle it. 
Watch how the 'role' column (which the below shows that it is a private method, even though
it's just a column in the users table) gets handled by the different versions. 
Rails 2.3.2 throws an error when first getting it, 2.1.2 doesn't. 
Both update their classes to show that its not a private method after it has been set once!

In Rails 2.3.2:
=====================================
Loading development environment (Rails 2.3.2)
>> cols = User.columns.map {|c| c.name}
=> ["id", "name", "login", "email", "crypted_password", "salt", "created_at", "updated_at", "remember_token", "remember_token_expires_at", "role"]
>> cols.map {|c| User.private_instance_methods.include?(c)}
=> [false, false, false, false, false, false, false, false, false, false, true]
>> u = User.new
#<User id: nil, name: nil, login: nil, email: nil, crypted_password: nil, salt: nil, created_at: nil, updated_at: nil, remember_token: nil, remember_token_expires_at: nil, role: nil>
=> #<User id: nil, name: nil, login: nil, email: nil, crypted_password: nil, salt: nil, created_at: nil, updated_at: nil, remember_token: nil, remember_token_expires_at: nil, role: nil>
>> u.role
NoMethodError: Attempt to call private method
	from /Library/Ruby/Gems/1.8/gems/activerecord-2.3.2/lib/active_record/attribute_methods.rb:236:in `method_missing'
	from (irb):4
>> cols.map {|c| User.private_instance_methods.include?(c)}
=> [false, false, false, false, false, false, false, false, false, false, true]
>> u.role = 'hello'
=> "hello"
>> u.role
=> "hello"
>> cols.map {|c| User.private_instance_methods.include?(c)}
=> [false, false, false, false, false, false, false, false, false, false, false]


In Rails 2.1.2:
=====================================
Loading development environment (Rails 2.1.2)
>> cols = User.columns.map {|c| c.name}
=> ["id", "name", "login", "email", "crypted_password", "salt", "created_at", "updated_at", "remember_token", "remember_token_expires_at", "role"]
>> cols.map {|c| User.private_instance_methods.include?(c)}
=> [false, false, false, false, false, false, false, false, false, false, true]
>> u = User.new
#<User id: nil, name: nil, login: nil, email: nil, crypted_password: nil, salt: nil, created_at: nil, updated_at: nil, remember_token: nil, remember_token_expires_at: nil, role: nil>
=> #<User id: nil, name: nil, login: nil, email: nil, crypted_password: nil, salt: nil, created_at: nil, updated_at: nil, remember_token: nil, remember_token_expires_at: nil, role: nil>
>> u.role
=> nil
>> cols.map {|c| User.private_instance_methods.include?(c)}
=> [false, false, false, false, false, false, false, false, false, false, false]
>> u.role = 'hello'
=> "hello"
>> u.role
=> "hello"
>> cols.map {|c| User.private_instance_methods.include?(c)}
=> [false, false, false, false, false, false, false, false, false, false, false]