Cannot display .kml file

I am trying to embed a .kml file (uploaded in my server) in a page and I am getting a blue frame with no content.
If a use the example code it works fine.
More specifically, for these two lines

[flexiblemap src=”http://snippets.webaware.com.au/maps/example-toronto.kml” width=”500″ height=”400″]
[flexiblemap src=”http://nature4culture.gr/wp-content/uploads/maps/Mesologgi.kml” width=”500″ height=”400″]

I get this page:
http://nature4culture.gr/?page_id=177

Any ideas??
Thanks in advance

http://ww.wp.xz.cn/plugins/wp-flexible-map/