>> a = Book.new(:id => 3000)
=> #<Book:0x2485380 @new_record=true, @attributes={"name"=>nil, "asin"=>nil, "chosha"=>nil, "shuppansha"=>nil}>
>> a.save
=> true
>> a.id
=> 1
>>

Rails 1.2.6なんですけど、主キーに値を放り込む方法ないですか？