Paperclip duplicates uploaded images

Hi,

I’m using rails3 with paperclip to upload multiple images as in
http://www.emersonlackey.com/article/paperclip-with-rails-3

The problem is, every image is duplicated upon create/update, that is,
saved twice to the db (and afterwards displayed twice in the view as a
result)
In other pages, and even in the same page as well, I also have a single
upload file, which works fine.

As a rails newbie, I don’t really know where to look at - is it
controller’s fault because I also merge attributes, or does paperclip
manages this by itself?

Help is very appreciated.