title: special price - how to remove in mass?
body: <p>I hase set some special price, with a start date, and no end date.
  Now I want to remove all the special price.
  so no discount.</p>
  
  <p>I went to the catalog view, I select ALL products, and clicked on "change attributes".
  I've check the "updated" checkbox beside start date, and special price.
  then I click apply.</p>
  
  <p>I can see the special price disappeared, but... on the front end, I can still see the promotion!
  How is it possible?
  Now note that If I select a product on the backoffice, and If I click on "save" (without editing anything) then it works on the front end!!</p>
  
  <p>Of course I re-indexed everything and cleared the cache.
  I have 20k products so I cannot select all products one by one to click on "save"</p>
  
  <p>thaks for your help
  Rod</p>