News Calendar shows articles twice

[Willette]

Hi,
first of all thanks a lot for this beautiful module, that I'm using with great satisfaction on this website http://www.sanlazzarosociale.it in the homepage.

I've just noticed that articles you see on Dec. 1 are also shown on Nov. 1, but those articles are saved with article created date set to Dec. 1 (my module is set with no cache and ordered by article created date).
Have you any idea what could be the problem?

Regards