The key question then is what happens if you had enabled it in Leopard and then you install Snow Leopard as an in-place upgrade. It looks like Apple meant to h

The key question then is what happens if you had enabled it in Leopard and then you install Snow Leopard as an in-place upgrade. It looks like Apple meant to have the setting revert, so that guest logins had to be reenabled. Instead, you let your friend login to the (still-enabled) guest account and then...