Errors::SignatureDoesNotMatch, AWS-SDK gem for S3 support on paperclip 3.0.1 and rails 3.2

I'm migrating my app from Rails 3.0.9 to 3.2.3 and ruby 1.9.3. I was using paperclip(2.3.11) with aws-s3 gem to store my pictures. Now I want to use the last version of paperclip(3.0.1) and then I have to use aws-sdk gem. I've set my aws.yml file as: ``` development: &development bucket: bucket_name_for_dev access_key_id: ***** secret_access_key: ******* staging: <<: *development bucket: bucket_name_for_staging production: <<: *development bucket: bucket_name_for_prod ``` my model contains : ``` has_attached_file :picture, :styles => { :medium => "300x300>", :thumb => "50x50>" }, :default_url => 'picture_missing.png', :storage => :s3, :bucket => "bucket_name_for_dev", :s3_credentials => Rails.root.join("config/aws.yml"), :path => "/presentation_pictures/:id/:style/:filename", :url => ":s3_eu_url" attr_accessible :picture attr_accessor :picture_url ``` When trying to upload a file, I get the error: `AWS::S3::Errors::SignatureDoesNotMatch` `The request signature we calculated does not match the signature you provided. Check your key and signing method.` I verified that my keys are accessible and set to the right value. Here is also what I get from console: ``` [paperclip] Saving attachments. [paperclip] saving /presentation_pictures/43/original/Image_1.png [AWS S3 200 0.813272 0 retries] put_object(:acl=>:public_read,:bucket_name=>"*******_dev",:content_type=>"image/png",:data=>#<Paperclip::UploadedFileAdapter:0x2e144b4 @target=#<ActionDispatch::Http::UploadedFile:0x2dbb1fc @original_filename="Image 1.png", @content_type="image/png", @headers="Content-Disposition: form-data; name=\"presentation_picture[picture]\"; filename=\"Image 1.png\"\r\nContent-Type: image/png\r\n", @tempfile=#<File:/var/folders/tb/tbmv4LE9EwGNPr1QqU2S0E+++TI/-Tmp-/RackMultipart20120407-33502-1gajfe9>>, @tempfile=#<File:/var/folders/tb/tbmv4LE9EwGNPr1QqU2S0E+++TI/-Tmp-/Image 1.png20120407-33502-an4dcy>>,:key=>"presentation_pictures/43/original/Image_1.png") ``` Do you have any idea from where could come this problem? Thx