Hi team,
With the Subsites module installed and several subsites present, you'll often find running dev/build marks your '/home' controller pages as 'changed' and sets the top-level URLSegments to home-2, home-3, home-4.
Try this in your _config.php:
SiteTree::set_create_default_pages(FALSE);
See http://open.silverstripe.org/ticket/6251 in TRAC.
Cheers, Matt