http://www.biblegateway.com/passage/?search=Mark%206:11;&version=6;
Here it is in Spanish. The difference I believe is from the actual translated work. Reina and Valera (Catholic Monks) used the Textus Receptus. If the Douay is Catholic then it also used the received text...until they later changed to the Sinaiticus and the Vaiticanus.
The King James uses the Received Text (Textus Receptus) as well.
Over my head. I need another lifetime to study up. I have the KJ and the NIV and I am not so fond of the NIV. A friend recommended the Douay which I'd like to get. Which is your preferred version?