Thanks for your answer but that does not give me warm feelings. 12 hours after the changes in DNS, WordPress still shows that DNS has not taken on this side.
Then, when I type http://immobilierfloride.info the URL goes to WordPress but at the wrong address. It shows this in the URL address: http://en.wordpress.com/typo/?subdomain=immobilier-floride, where the subdomain is reversed.
When you type instead http://en.wordpress.com/typo/?subdomain=florideimmobilier, then it goes to the correct WordPress site which is florideimmobilier.wordpress.com.
This tells me that there is something wrong in your DNS list. So how does this get fixed?