KML Invalid document

Hi,
I’m trying to use a KML file build but when I load the page I have an error with “INVALID_COCUMENT”. You can have a look here:
http://cicciobello.wp.foodle.be/acces/
The KLM is well publicated : https://docs.google.com/file/d/0B505RxhjkU8RclNSUGVIMFZzeTQ/edit

But seems that is not a valid format.
When I copy paste the URL, I have the map on the screen; seems that the KML has valid format. And if not, How can I build a correct one ?

I don’t know where to find, my KML seems to be good.
Any idea ?
Thx in advance.

Andrea

http://wordpress.org/extend/plugins/comprehensive-google-map-plugin/