If those files are not present in the new public_html folder, it could be a few reasons.
1) Make sure /home/creator/domains/default is present, and is world readable (755). Replace creator with the name of the account that created the new user.
2) possibly the user is over quotas instantly. This can happen if other files exist on the file system, and were set to his UID number (which wouldn't have been assigned to any user).. but when the user was created, it happened to use the same UID number, thus those "other" files become his.
This is the guide to find those files: http://help.directadmin.com/item.php?id=39
3) Lastly, make sure you have free space on your disk