LLTD for some reason has not been updated for service pack 3.
To access Vista directories you need to ensure all permissions are in place. You need to enable network discovery and sharing. All shared folders other than Public need to have their permissions changed (no not share roots of hard drives)
Simply right click folder you wish to access on Vista machine select share. At the top you will see a drop down menu with nothing in it. Click down and select Everyone. You will then need to select an option other than read so select co owner if you want full control then click share and you will find your folder is now accessable