I only realised a few days ago as I looked into someone elses site that the standard url on an xmap sitemap for the homepage is /home
Both this and the standard / urls exist and it can lead to problems when getting indexed.
Here's how to sort it out...
Open up your ftp client and go to both files:
Search the files for the line:
$link = Xmap::getItemLink($node);
Just after this line, add the line:
$link = str_replace('/home', '/', $link);
This will replace the /home link with the root of your domain.
If you use the .html prefix in global configuration then add the .html to the end of /home
Nothing worse than search engines finding pages you didn't think were there!