Ruby roo gem uploading excels

Right so I've checked out Roo. Great gem and all and have a really basic application that doesn't have no models. And basic controller, class and view and I can't seem to get a spreadsheet to upload as I am getting OLE2 signature is invalid error. I have the following basic setup
Controller

class SpreadsheetServiceController < ApplicationController

  def new
  end

  def create    
    parser = SpreadsheetTagService.new(params[:spreadsheet][:file])

    respond_to do |format|
      format.all {render :json => 'Done'}
    end
  end
end 

SpreadsheetTagService

 class SpreadsheetTagService 
  include Roo

  def initialize(uploaded_file)
    @tmp_destination = "#{Rails.root}/tmp/tag-import.xls"
    @file_path = save_file_to_tmp(uploaded_file)
    @file = File.new(@file_path)
    read_file(@file)
  end 

  private 
    def save_file_to_tmp(uploaded_file)
      FileUtils.mv(uploaded_file.tempfile.path, @tmp_destination )
      @tmp_destination
    end

    def read_file(file)
      @spreadsheet = open_spreadsheet(file)
      @spreadsheet.each_with_pagename do |name,sheet|    
        Rails.logger.debug( sheet )
      end    
    end

    def open_spreadsheet(file)
      case File.extname(file.path)
        when ".csv" then Csv.new(file.path, nil, :ignore)
        when ".xls" then Excel.new(file.path, nil, :ignore)
        when ".xlsx" then Excelx.new(file.path, nil, :ignore)
        else raise "Unknown file type: #{file.original_filename}"
      end
    end

end  

View

<%= form_tag spreadsheetupload_url, multipart: true do %>
  <%= file_field_tag :file %>
  <%= submit_tag "Import" %>
<% end %>

Another Method

require 'spreadsheet'
require 'fileutils'
require 'iconv'

def excel_import

 tmp = params[:dump][:excel_file].tempfile

 Spreadsheet.client_encoding = 'UTF-8'

 book = Spreadsheet.open tmp.path

 sheet1 = book.worksheet 0
 sheet1.each do |row|
 TimeSheet.new(:ac_no => row[0]).save
 end
end

FileUtils.rm tmp.path