Comment 29 for bug 592610

Via nautilus is usershare. Via smb.conf is root share. Try to set permissions of home to 755 and make a share /home/public
If you make a public share samba uses nobody/other as user to change to that directory. Its the last digit of dir permissions that is used. You can see that if you run samba with debug level.
 But the best way is to use the smb.config edits from above the you can share folders in /home and external ext4 drive like i do.