Why this Ruby query

I'm trying to create an object with this data. Problem is that as you see in code it isn't saving the data I'm giving nor the specified Id. Any ideas?

>> Attachment.create(:id => 50, :attachment_file_name => "tumblr_lbxifqK2LT1qa0qyy.jpg",  
:attachment_content_type  => "image/jpeg", :attachment_file_size=>80960, 
:attachment_updated_at => "2010-12-22 07:39:01", :created_at => "2010-12-22 07:39:02", 
:updated_at => "2011-03-07 02:14:05", :post_id => nil, :about_me => nil, :is_nsfw => nil, 
:attachable_id => nil, :attachable_type => nil, :is_default => nil, :temp_token => nil, 
:user_id => 1, :description => nil, :visits => nil)

=> #<Attachment id: 451, shortcut: "cjke", attachment_file_name: nil, 
attachment_content_type: nil, attachment_file_size: nil, attachment_updated_at: nil, 
created_at: "2011-03-07 04:46:15", updated_at: "2011-03-07 04:46:15", post_id: nil, 
about_me: nil, is_nsfw: nil, attachable_id: nil, attachable_type: nil, is_default: nil, 
temp_token: nil, user_id: 1, description: nil, visits: nil>

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UPDATED: It's saving the username. Seems like what is not saving is the related paperclip info and the specified ID.

id is a protected attribute when dealing with ActiveRecord and Rails; you can't assign it a value manually.