How to customize version filename in Carrierwave?

I have a strange issue. I am trying to use master branch of carrierwave with Rails 3.2.xx project. I need to customize filenames of the versions. But when I add full_filename method in the version block, my original file also gets reduced to the dimensions specified for version.

When I remove full_filename method, it all works as expected, but thumb filename has thumb_ prefix which I don't want.

Is there a new way to customize version filenames. I have been using this way successfully in 0.10.0 and before.

Below is my uploader. This is a generated uploader with store_dir overrides.

class TestUploader < CarrierWave::Uploader::Base

  # Include RMagick or MiniMagick support:
  # include CarrierWave::RMagick
  include CarrierWave::MiniMagick

  # Choose what kind of storage to use for this uploader:
  # storage :file
  storage :fog

  # Override the directory where uploaded files will be stored.
  # This is a sensible default for uploaders that are meant to be mounted:
  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  # Create different versions of your uploaded files:

  version :thumb do
    process :resize_to_fit => [200, 200]

    def store_dir
      "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}/#{version_name}"
    end

    def full_filename(for_file = model.logo.file)
      super(for_file).sub(version_name.to_s + '_', '')
    end
  end

end

Any ideas? All I need to do is to remove version_name part from its filename, since I am saving the versions in separate folders. I searched through Wiki and internet, but couldn't find a new way of doing this.