[Plugin: Good Old Gallery] Custom fields not work

Hello,
I added the gallery code [good-old-gallery id=”XXX”] in a custom field but does not work, the images appear as a list. If I write the code in the post works correctly but is duplicated (because the code is written in the custom field and in the article).

Can you help me?
Thanks.

http://wordpress.org/extend/plugins/good-old-gallery/